An unexpected error condition occurred. Please [file a bug report](https://bugzilla.xamarin.com/enter_bug.cgi?product=iOS) with as much information as possible, including:
* Full build logs, with maximum verbosity (e.g. `-v -v -v -v` in the **Additional mtouch arguments**);
* A minimal test case that reproduce the error; and
* All version informations
The easiest way to get exact version information is to use the **Xamarin Studio** menu, **About Xamarin Studio** item, **Show Details** button and copy/paste the version informations (you can use the **Copy Information** button).
<h3><aname="MT0001"/>MT0001: '-devname' was provided without any device-specific action</h3>
This is a warning that is emitted if -devname is passed to mtouch when no device-specific action (-logdev/-installdev/-killdev/-launchdev/-listapps) was requested.
<h3><aname="MT0002"/>MT0002: Could not parse the environment variable *.</h3>
This error happens if you try to set an invalid environment key=value variable pair. The correct format is: `mtouch --setenv=VARIABLE=VALUE`
<h3><aname="MT0003"/>MT0003: Application name '*.exe' conflicts with an SDK or product assembly (.dll) name.</h3>
The executable assembly's name and the application's name can't match the name of any dll in the app. Please modify the name of your executable.
<h3><aname="MT0004"/>MT0004: New refcounting logic requires SGen to be enabled too.</h3>
If you enable the refcounting extension you must also enable the SGen garbage collector in the project's iOS Build options (Advanced tab).
Starting with Xamarin.iOS 7.2.1 this requirement has been lifted, the new refcounting logic can be enabled with both Boehm and SGen Garbage Collectors.
<h3><aname="MT0005"/>MT0005: The output directory * does not exist.</h3>
Please create the directory.
<h3><aname="MT0006"/>MT0006: There is no devel platform at *, use --platform=PLAT to specify the SDK.</h3>
Xamarin.iOS cannot find the SDK directory at the location mentioned in the error message. Please verify that the path is correct.
<h3><aname="MT0007"/>MT0007: The root assembly * does not exist.</h3>
Xamarin.iOS cannot find the assembly at the location mentioned in the error message. Please verify that the path is correct.
<h3><aname="MT0008"/>MT0008: You should provide one root assembly only, found # assemblies: *.</h3>
More than one root assembly was passed to mtouch, while there can be only one root assembly.
<h3><aname="MT0009"/>MT0009: Error while loading assemblies: *.</h3>
An error occurred while loading the assemblies the root assembly references. More information may be provided in the build output.
<h3><aname="MT0010"/>MT0010: Could not parse the command line arguments: *.</h3>
An error occurred while parsing the command line arguments. Please verify that they are all correct.
<h3><aname="MT0011"/>MT0011: * was built against a more recent runtime (*) than MonoTouch supports.</h3>
This warning is typically reported because the project has a reference to a class library that was not built using the Xamarin.iOS BCL.
The same way an app using the .NET 4.0 SDK may not work on a system only supporting .NET 2.0, a library built using .NET 4.0 may not work on Xamarin.iOS, it may use API not present on Xamarin.iOS.
The general solution is to build the library as a Xamarin.iOS Class Library. This can be accomplished by creating a new Xamarin.iOS Class Library project and add all the source files to it. If you do not have the source code for the library, you should contact the vendor and request that they provide a Xamarin.iOS-compatible version of their library.
<h3><aname="MT0012"/>MT0012: Incomplete data is provided to complete *.</h3>
This error is not reported anymore in the current version of Xamarin.iOS.
<h3><aname="MT0013"/>MT0013: Profiling support requires sgen to be enabled too.</h3>
SGen (--sgen) must be enabled if profiling (--profiling) is enabled.
<h3><aname="MT0014"/>MT0014: The iOS * SDK does not support building applications targeting *.</h3>
This can happen in the following circumstances:
* ARMv6 is enabled and Xcode 4.5 or later is installed.
* ARMv7s is enabled and Xcode 4.4 or earlier is installed.
Please verify that the installed version of Xcode supports the selected architectures.
An invalid ABI was passed to mtouch. Please specify a valid ABI.
<h3><aname="MT0016"/>MT0016: The option * has been deprecated.</h3>
The mentioned mtouch option has been deprecated and will be ignored.
<h3><aname="MT0017"/>MT0017: You should provide a root assembly.</h3>
It is required to specify a root assembly (typically the main executable) when building an app.
<h3><aname="MT0018"/>MT0018: Unknown command line argument: *.</h3>
Mtouch does not recognize the command line argument mentioned in the error message.
<h3><aname="MT0019"/>MT0019: Only one --[log|install|kill|launch]dev or --[launch|debug]sim option can be used.</h3>
There are several options for mtouch that can't be used simultaneously:
- --logdev
- --installdev
- --killdev
- --launchdev
- --launchdebug
- --launchsim
<h3><aname="MT0020"/>MT0020 The valid options for '*' are '*'.</h3>
<h3><aname="MT0021"/>MT0021 Cannot compile using gcc/g++ (--use-gcc) when using the static registrar (this is the default when compiling for device). Either remove the --use-gcc flag or use the dynamic registrar (--registrar:dynamic).</h3>
<h3><aname="MT0022"/>MT0022 The options '--unsupported--enable-generics-in-registrar' and '--registrar' are not compatible.</h3>
Remove both the options `--unsupported--enable-generics-in-registrar` and `--registrar`. Starting with Xamarin.iOS 7.2.1 the default registrar supports generics.
<h3><aname="MT0023"/>MT0023 Application name '*.exe' conflicts with another user assembly.</h3>
The executable assembly's name and the application's name can't match the name of any dll in the app. Please modify the name of your executable.
<h3><aname="MT0024"/>MT0024 Could not find required file '*'.</h3>
<h3><aname="MT0025"/>MT0025 No SDK version was provided. Please add `--sdk=X.Y` to specify which iOS SDK should be used to build your application.</h3>
<h3><aname="MT0026"/>MT0026 Could not parse the command line argument '*': *</h3>
<h3><aname="MT0027"/>MT0027 The options '*' and '*' are not compatible.</h3>
<h3><aname="MT0028"/>MT0028 Cannot enable PIE (-pie) when targeting iOS 4.1 or earlier. Please disable PIE (-pie:false) or set the deployment target to at least iOS 4.2</h3>
<h3><aname="MT0029"/>MT0029: REPL (--enable-repl) is only supported in the simulator (--sim).</h3>
REPL is only supported if you're building for the simulator. This means that if you pass `--enable-repl` to mtouch, you must also pass `--sim`.
<h3><aname="MT0030"/>MT0030: The executable name (*) and the app name (*) are different, this may prevent crash logs from getting symbolicated properly.</h3>
When Xcode symbolicates (translates memory addresses to function names and file/line numbers) the process may fail if the executable and app have different names (without the extension).
To fix this either change 'Application Name' in the project's Build/iOS Application options, or change 'Assembly Name' in the project's Build/Output options.
<h3><aname="MT0031"/>MT0031: The command line arguments '--enable-background-fetch' and '--launch-for-background-fetch' require '--launchsim' too.</h3>
<h3><aname="MT0032"/>MT0032: The option '--debugtrack' is ignored unless '--debug' is also specified.</h3>
<h3><aname="MT0033"/>MT0033 A Xamarin.iOS project must reference either monotouch.dll or Xamarin.iOS.dll</h3>
<h3><aname="MT0034"/>MT0034 Cannot include both 'monotouch.dll' and 'Xamarin.iOS.dll' in the same Xamarin.iOS project - '*' is referenced explicitly, while '*' is referenced by '*'.</h3>
<h3><aname="MT0036"/>MT0036 Cannot launch a * simulator for a * app. Please enable the correct architecture(s) in your project's iOS Build options (Advanced page).</h3>
<h3><aname="MT0037"/>MT0037 monotouch.dll is not 64-bit compatible. Either reference Xamarin.iOS.dll, or do not build for a 64-bit architecture (ARM64 and/or x86_64).</h3>
<h3><aname="MT0038"/>MT0038 The old registrars (--registrar:oldstatic|olddynamic) are not supported when referencing Xamarin.iOS.dll.</h3>
<h3><aname="MT0040"/>MT0040 Could not find the assembly '*', referenced by '*'.</h3>
<h3><aname="MT0041"/>MT0041 Cannot reference both 'monotouch.dll' and 'Xamarin.iOS.dll'.</h3>
<h3><aname="MT0042"/>MT0042 No reference to either monotouch.dll or Xamarin.iOS.dll was found. A reference to monotouch.dll will be added.</h3>
<h3><aname="MT0043"/>MT0043: The Boehm garbage collector is currently not supported when referencing 'Xamarin.iOS.dll'. The SGen garbage collector has been selected instead.</h3>
Only the SGen garbage collector is supported with Unified projects. Ensure there are no additional mtouch flags specifying Boehm as the garbage collector.
<h3><aname="MT0044"/>MT0044: --listsim is only supported with Xcode 6.0 or later.</h3>
Install a newer Xcode version.
<h3><aname="MT0045"/>MT0045: --extension is only supported when using the iOS 8.0 (or later) SDK.</h3>
<!-- MT0046 is not reported anymore -->
<h3><aname="MT0047"/>MT0047: The minimum deployment target for Unified applications is 5.1.1, the current deployment target is '*'. Please select a newer deployment target in your project's iOS Application options.</h3>
<!-- MT0048 is not reported anymore -->
<h3><aname="MT0049"/>MT0049: *.framework is supported only if deployment target is 8.0 or later. * features might not work correctly.</h3>
The specified framework is not supported in the iOS version the deployment target refers to. Either update the deployment target to a newer iOS version, or remove usage of the specified framework from the app.
<!-- MT0050 is not reported anymore -->
<h3><aname="MT0051"/>MT0051: Xamarin.iOS * requires Xcode 5.0 or later. The current Xcode version (found in *) is *.</h3>
Install a newer Xcode.
<h3><aname="MT0052"/>MT0052: No command specified.</h3>
No action was specified for mtouch.
<!-- 0053 is used by mmp -->
<h3><aname="MT0054"/>MT0054: Unable to canonicalize the path '*': *</h3>
This is an internal error. If you see this error, please file a bug [http://bugzilla.xamarin.com](https://bugzilla.xamarin.com/enter_bug.cgi?product=iOS).
<h3><aname="MT0055"/>MT0055: The Xcode path '*' does not exist.</h3>
The Xcode path passed using `--sdkroot` does not exist. Please specify a valid path.
<h3><aname="MT0056"/>MT0056: Cannot find Xcode in the default location (/Applications/Xcode.app). Please install Xcode, or pass a custom path using --sdkroot <path>.</h3>
<h3><aname="MT0057"/>MT0057: Cannot determine the path to Xcode.app from the sdk root '*'. Please specify the full path to the Xcode.app bundle.</h3>
The path passed using `--sdkroot` does not specify a valid Xcode app. Please specify a path to an Xcode app.
<h3><aname="MT0058"/>MT0058: The Xcode.app '*' is invalid (the file '*' does not exist).</h3>
The path passed using `--sdkroot` does not specify a valid Xcode app. Please specify a path to an Xcode app.
<h3><aname="MT0059"/>MT0059: Could not find the currently selected Xcode on the system: *</h3>
<h3><aname="MT0060"/>MT0060: Could not find the currently selected Xcode on the system. 'xcode-select --print-path' returned '*', but that directory does not exist.</h3>
<h3><aname="MT0061"/>MT0061: No Xcode.app specified (using --sdkroot), using the system Xcode as reported by 'xcode-select --print-path': *</h3>
This is a informational warning, explaining which Xcode will be used, since none was specified.
<h3><aname="MT0062"/>MT0062: No Xcode.app specified (using --sdkroot or 'xcode-select --print-path'), using the default Xcode instead: *</h3>
This is a informational warning, explaining which Xcode will be used, since none was specified.
<h3><aname="MT0063"/>MT0063: Cannot find the executable in the extension * (no CFBundleExecutable entry in its Info.plist)</h3>
Every Info.plist must have an executable (using the CFBundleExecutable entry), however an entry should be generated automatically during the build.
This usually indicates a bug in Xamarin.iOS; please file a bug report at http://bugzilla.xamarin.com with a test case.
<h3><aname="MT0064"/>MT0064: Xamarin.iOS only supports embedded frameworks with Unified projects.</h3>
Xamarin.iOS only supports embedded frameworks when using the Unified API; please update your project to use the Unified API.
<h3><aname="MT0065"/>MT0065: Xamarin.iOS only supports embedded frameworks when deployment target is at least 8.0 (current deployment target: * embedded frameworks: *)</h3>
Xamarin.iOS only supports embedded frameworks when the deployment target is at least 8.0 (because earlier versions of iOS does not support embedded frameworks).
Please update the deployment target in the project's Info.plist to 8.0 or higher.
An invalid target framework was passed using the --target-framework argument. Please specify a valid target framework.
<h3><aname="MT0071"/>MT0071: Unknown platform: *. This usually indicates a bug in Xamarin.iOS; please file a bug report at http://bugzilla.xamarin.com with a test case.</h3>
This usually indicates a bug in Xamarin.iOS; please file a bug report at http://bugzilla.xamarin.com with a test case.
<h3><aname="MT0072"/>MT0072: Extensions are not supported for the platform '*'.</h3>
This usually indicates a bug in Xamarin.iOS; please file a bug report at http://bugzilla.xamarin.com with a test case.
<h3><aname="MT0073"/>MT0073: Xamarin.iOS * does not support a deployment target of * (the minimum is *). Please select a newer deployment target in your project's Info.plist.</h3>
The minimum deployment target is the one specified in the error message; please select a newer deployment target in the project's Info.plist.
If updating the deployment target is not possible, then please use an older version of Xamarin.iOS.
<h3><aname="MT0074"/>MT0074: Xamarin.iOS * does not support a minimum deployment target of * (the maximum is *). Please select an older deployment target in your project's Info.plist or upgrade to a newer version of Xamarin.iOS.</h3>
Xamarin.iOS does not support setting the minimum deployment target to a higher version than the version this particular version of Xamarin.iOS was built for.
Please select an older minimum deployment target in the project's Info.plist, or upgrade to a newer version of Xamarin.iOS.
<h3><aname="MT0078"/>MT0077: Incremental builds are enabled with a deployment target <8.0(currently*).Thisisnotsupported(theresultingapplicationwillnotlaunchoniOS9),sothedeploymenttargetwillbesetto8.0.</h3>
Incremental builds are only supported when the deployment target is at least 8.0 (because the resulting application will not launch on iOS 9 otherwise).
<h3><aname="MT0091"/>MT0091: This version of Xamarin.iOS requires the * SDK (shipped with Xcode *) when the managed linker is disabled. Either upgrade Xcode, or enable the managed linker.</h3>
This version of Xamarin.iOS requires the SDK specified in the error message if the managed linker is disabled.
This is because the app must be built with an SDK that contains all the native API the app uses, and if the managed linker is disabled, the app will use all the API shipped with this version Xamarin.iOS.
The recommended way to fix this error is to upgrade Xcode to get the required SDK.
A potential alternative solution is to enable the managed linker (although this may not work if your project uses API that was introduced in the required SDK).
A last-straw solution would be to use a different version of Xamarin.iOS, one that supports the SDK your project requires.
<h3><aname="MT0093"/>MT0093: Aot symbolication files could not be copied to the destination directory. Symbolication will not work with the application.</h3>
<h3><aname="MT1001"/>MT1001 Could not find an application at the specified directory</h3>
<h3><aname="MT1002"/>MT1002 Could not create symlinks, files were copied</h3>
<h3><aname="MT1003"/>MT1003 Could not kill the application '*'. You may have to kill the application manually.</h3>
<h3><aname="MT1004"/>MT1004 Could not get the list of installed applications.</h3>
<h3><aname="MT1005"/>MT1005 Could not kill the application '*' on the device '*': *- You may have to kill the application manually.</h3>
<h3><aname="MT1006"/>MT1006 Could not install the application '*' on the device '*': *.</h3>
<h3><aname="MT1007"/>MT1007 Failed to launch the application '*' on the device '*': *. You can still launch the application manually by tapping on it.</h3>
<h3><aname="MT1008"/>MT1008: Failed to launch the simulator</h3>
This error is reported if mtouch failed to launch the
simulator. This can happen sometimes because there is
already a stale or dead simulator process running.
The following command issued on the Unix command line can
<h3><aname="MT1009"/>MT1009 Could not copy the assembly '*' to '*': *</h3>
<h3><aname="MT1010"/>MT1010 Could not load the assembly '*': *</h3>
<h3><aname="MT1011"/>MT1011 Could not add missing resource file: '*'</h3>
<h3><aname="MT1012"/>MT1012 Failed to list the apps on the device '*': *</h3>
<h3><aname="MT1013"/>MT1013 Dependency tracking error: no files to compare. Please file a bug report at http://bugzilla.xamarin.com with a test case.</h3>
<h3><aname="MT1014"/>MT1014 Failed to re-use cached version of '*': *.</h3>
<h3><aname="MT1015"/>MT1015 Failed to create the executable '*': *</h3>
<h3><aname="MT1015"/>MT1015 Failed to create the executable '*': *</h3>
<h3><aname="MT1016"/>MT1016: Failed to create the NOTICE file because a directory already exists with the same name.</h3>
Remove the directory `NOTICE` from the project.
<h3><aname="MT1017"/>MT1017: Failed to create the NOTICE file: *.</h3>
<h3><aname="MT1018"/>MT1018: Your application failed code-signing checks and could not be installed on the device '*'. Check your certificates, provisioning profiles, and bundle ids. Probably your device is not part of the selected provisioning profile (error: 0xe8008015).</h3>
<h3><aname="MT1019"/>MT1019: Your application has entitlements not supported by your current provisioning profile and could not be installed on the device '*'. Please check the iOS Device Log for more detailed information (error: 0xe8008016).</h3>
This can happen if:
<ul>
<li>Your application has entitlements that the current provisioning profile does not support. <br/>
Possible solutions:
<ul>
<li>Specify a different provisioning profile that supports the entitlements your application needs.</li>
<li>Remove the entitlements not supported in current provisioning profile.</li>
</ul>
</li>
<li>The device you're trying to deploy to is not included in the provisioning profile you're using.<br/>
Possible solutions:
<ul>
<li>Create a new app from a template in Xcode, select the same provisioning profile, and deploy to same device. Sometimes Xcode can automatically refresh provisioning profiles with new devices (in other cases Xcode will ask you what to do).</li>
<li>Go to the iOS Dev Center and update the provisioning profile with the new device, then download the updated provisioning profile to your machine.</li>
</ul>
</li>
</ul>
In most cases more information about the failure will be printed to the iOS Device Log, which can help diagnosing the issue.
<h3><aname="MT1020"/>MT1020: Failed to launch the application '*' on the device '*': *</h3>
<h3><aname="MT1021"/>MT1021: Could not copy the file '*' to '*': {2}</h3>
A file could not be copied. The error message from the copy operation has more information about the error.
<h3><aname="MT1022"/>MT1022: Could not copy the directory '*' to '*': {2}</h3>
A directory could not be copied. The error message from the copy operation has more information about the error.
<h3><aname="MT1023"/>MT1023: Could not communicate with the device to find the application '*' : *</h3>
An error occurred when trying to lookup an application on device.
Things to try to solve this:
* Delete the application from the device and try again.
* Disconnect the device and reconnect it.
* Reboot the device.
* Reboot the Mac.
<h3><aname="MT1024"/>MT1024: The application signature could not be verified on device '*'. Please make sure that the provisioning profile is installed and not expired (error: 0xe8008017).</h3>
The device rejected the application install because the signature could not be verified.
Please make sure that the provisioning profile is installed and not expired.
<h3><aname="MT1025"/>MT1025: Could not list the crash reports on the device *.</h3>
An error occurred when trying to list the crash reports on the device.
Things to try to solve this:
* Delete the application from the device and try again.
* Disconnect the device and reconnect it.
* Reboot the device.
* Reboot the Mac.
* Synchronize the device with iTunes (this will remove any crash reports from the device).
<h3><aname="MT1026"/>MT1026: Could not download the crash report * from the device *.</h3>
An error occurred when trying to download the crash reports from the device.
Things to try to solve this:
* Delete the application from the device and try again.
* Disconnect the device and reconnect it.
* Reboot the device.
* Reboot the Mac.
* Synchronize the device with iTunes (this will remove any crash reports from the device).
<h3><aname="MT1027"/>MT1027: Can't use Xcode 7+ to launch applications on devices with iOS * (Xcode 7 only supports iOS 6+).</h3>
It is not possible to use Xcode 7+ to launch applications on devices with iOS version below 6.0.
Please use an older version of Xcode, or tap on the app manually to launch it.
<h3><aname="MT1028"/>MT1028: Invalid device specification: '*'. Expected 'ios', 'watchos' or 'all'.</h3>
The device specification passed using --device is invalid. Valid values are: 'ios', 'watchos' or 'all'.
<h3><aname="MT1029"/>MT1029: Could not find an application at the specified directory: *</h3>
The application path passed to --launchdev does not exist. Please specify a valid app bundle.
<h3><aname="MT1030"/>MT1030: Launching applications on device using a bundle identifier is deprecated. Please pass the full path to the bundle to launch.</h3>
It's recommended to pass the path to the app to launch on device instead of just the bundle id.
<h3><aname="MT1031"/>MT1031: Could not launch the app '*' on the device '*' because the device is locked. Please unlock the device and try again.</h3>
Please unlock the device and try again.
<!--
MT11xx DebugService.cs
-->
<h3><aname="MT1101"/>MT1101 Could not start app</h3>
<h3><aname="MT1102"/>MT1102 Could not attach to the app (to kill it): *</h3>
<h3><aname="MT1103"/>MT1103 Could not detach</h3>
<h3><aname="MT1104"/>MT1104 Failed to send packet: *</h3>
<h3><aname="MT1106"/>MT1106 Could not get list of applications on the device: Request timed out.</h3>
<h3><aname="MT1107"/>MT1107: Application failed to launch: *</h3>
Please check if your device is locked.
If you're deploying an enterprise app or using a free provisioning profile, you might have trust the developer (this is explained <ahref="http://stackoverflow.com/a/30726375/183422">here</a>).
<h3><aname="MT1108"/>MT1108: Could not find developer tools for this XX (YY) device.</h3>
A few operations from mtouch require the <tt>DeveloperDiskImage.dmg</tt> file to be present. This
file is part of Xcode and is usually located relative to the
SDK that you are using to build against, in
the <tt>Xcode.app/Contents/Developer/iPhoneOS.platform/DeviceSupport/VERSION/DeveloperDiskImage.dmg</tt>.
This error can happen either because you do not have a
DeveloperDiskImage.dmg that matches the device that you have
connected.
<h3><aname="MT1109"/>MT1109: Application failed to launch because the device is locked. Please unlock the device and try again.</h3>
Please check if your device is locked.
<h3><aname="MT1110"/>MT1110: Application failed to launch because of iOS security restrictions. Please ensure the developer is trusted.</h3>
If you're deploying an enterprise app or using a free provisioning profile, you might have trust the developer (this is explained <ahref="http://stackoverflow.com/a/30726375/183422">here</a>).
<!--
MT12xx simcontroller.cs
-->
<h3><aname="MT1201"/>MT1201: Could not load the simulator: *</h3>
<h3><aname="MT1216"/>MT1216: Could not find the simulator UDID '*'.</h3>
<h3><aname="MT1217"/>MT1217: Could not load the app bundle at '*'.</h3>
<h3><aname="MT1218"/>MT1218: No bundle identifier found in the app at '*'.</h3>
<h3><aname="MT1219"/>MT1219: Could not find the simulator for '*'.</h3>
<h3><aname="MT1220"/>MT1220: Could not find the latest simulator runtime for device '*'.</h3>
This usually indicates a problem with Xcode.
Things to try to fix this:
* Use the simulator once in Xcode.
* Pass an explicit SDK version using --sdk <version>.
* Reinstall Xcode.
<h3><aname="MT1221"/>MT1221: Could not find the paired iPhone simulator for the WatchOS simulator '*'.</h3>
When launching a WatchOS app in a WatchOS simulator, there must be a paired iOS Simulator as well.
Watch simulators can be paired with iOS Simulators using Xcode's Devices UI (menu Window -> Devices).
<!--
MT13xx [LinkWith]
-->
<h3><aname="MT1301"/>MT1301 Native library `*` (*) was ignored since it does not match the current build architecture(s) (*)</h3>
<h3><aname="MT1302"/>MT1302 Could not extract the native library '*' from '+'. Please ensure the native library was properly embedded in the managed assembly (if the assembly was built using a binding project, the native library must be included in the project, and its Build Action must be 'ObjcBindingNativeLibrary').</h3>
<h3><aname="MT1303"/>MT1303: Could not decompress the native framework '*' from '*'. Please review the build log for more information from the native 'zip' command.</h3>
Could not decompress the specified native framework from the binding library.
Please review the bulid log for more information about this failure from the native 'zip' command.
<h3><aname="MT1304"/>MT1304: The embedded framework '*' in * is invalid: it does not contain an Info.plist.</h3>
The specified embedded framework does not contain an Info.plist, and is therefore not a valid framework.
Please make sure the framework is valid.
<h3><aname="MT1305"/>MT1305: The binding library '*' contains a user framework (*), but embedded user frameworks require iOS 8.0 (the current deployment target is *). Please set the deployment target in the Info.plist file to at least 8.0.</h3>
The specified binding library contains an embedded framework, but Xamarin.iOS only supports embedded frameworks on iOS 8.0 or later.
Please set the deployment target in the Info.plist file to at least 8.0 to solve this error (or don't use embedded frameworks).
<!--
MT14xx CrashReports.cs
-->
<h3><aname="MT1400"/>MT1400: Could not open crash report service: AFCConnectionOpen returned *</h3>
An error occurred when trying to access crash reports from the device.
Things to try to solve this:
* Delete the application from the device and try again.
* Disconnect the device and reconnect it.
* Reboot the device.
* Reboot the Mac.
* Synchronize the device with iTunes (this will remove any crash reports from the device).
<h3><aname="MT1401"/>MT1401: Could not close crash report service: AFCConnectionClose returned *</h3>
An error occurred when trying to access crash reports from the device.
Things to try to solve this:
* Delete the application from the device and try again.
* Disconnect the device and reconnect it.
* Reboot the device.
* Reboot the Mac.
* Synchronize the device with iTunes (this will remove any crash reports from the device).
<h3><aname="MT1402"/>MT1402: Could not read file info for *: AFCFileInfoOpen returned *</h3>
An error occurred when trying to access crash reports from the device.
Things to try to solve this:
* Delete the application from the device and try again.
* Disconnect the device and reconnect it.
* Reboot the device.
* Reboot the Mac.
* Synchronize the device with iTunes (this will remove any crash reports from the device).
<h3><aname="MT1403"/>MT1403: Could not read crash report: AFCDirectoryOpen (*) returned: *</h3>
An error occurred when trying to access crash reports from the device.
Things to try to solve this:
* Delete the application from the device and try again.
* Disconnect the device and reconnect it.
* Reboot the device.
* Reboot the Mac.
* Synchronize the device with iTunes (this will remove any crash reports from the device).
<h3><aname="MT1404"/>MT1404: Could not read crash report: AFCFileRefOpen (*) returned: *</h3>
An error occurred when trying to access crash reports from the device.
Things to try to solve this:
* Delete the application from the device and try again.
* Disconnect the device and reconnect it.
* Reboot the device.
* Reboot the Mac.
* Synchronize the device with iTunes (this will remove any crash reports from the device).
<h3><aname="MT1405"/>MT1405: Could not read crash report: AFCFileRefRead (*) returned: *</h3>
An error occurred when trying to access crash reports from the device.
Things to try to solve this:
* Delete the application from the device and try again.
* Disconnect the device and reconnect it.
* Reboot the device.
* Reboot the Mac.
* Synchronize the device with iTunes (this will remove any crash reports from the device).
<h3><aname="MT1406"/>MT1406: Could not list crash reports: AFCDirectoryOpen (*) returned: *</h3>
An error occurred when trying to access crash reports from the device.
Things to try to solve this:
* Delete the application from the device and try again.
* Disconnect the device and reconnect it.
* Reboot the device.
* Reboot the Mac.
* Synchronize the device with iTunes (this will remove any crash reports from the device).
<!--
MT16xx MachO.cs
-->
<h3><aname="MT1600"/>MT1600: Not a Mach-O dynamic library (unknown header '0x*'): *.</h3>
An error occurred while processing the dynamic library in question.
Please make sure the dynamic library is a valid Mach-O dynamic library.
The format of a library can be verified using the `file` command from a terminal:
file -arch all -l /path/to/library.dylib
<h3><aname="MT1601"/>MT1601: Not a static library (unknown header '*'): *.</h3>
An error occurred while processing the static library in question.
Please make sure the static library is a valid Mach-O static library.
The format of a library can be verified using the `file` command from a terminal:
file -arch all -l /path/to/library.a
<h3><aname="MT1602"/>MT1602: Not a Mach-O dynamic library (unknown header '0x*'): *.</h3>
An error occurred while processing the dynamic library in question.
Please make sure the dynamic library is a valid Mach-O dynamic library.
The format of a library can be verified using the `file` command from a terminal:
file -arch all -l /path/to/library.dylib
<h3><aname="MT1603"/>MT1603: Unknown format for fat entry at position * in *.</h3>
An error occurred while processing the fat archive in question.
Please make sure the fat archive is valid.
The format of a fat archive can be verified using the `file` command from a terminal:
file -arch all -l /path/to/file
<h3><aname="MT1604"/>MT1604: File of type * is not a MachO file (*).</h3>
An error occurred while processing the MachO file in question.
Please make sure the file is a valid Mach-O dynamic library.
The format of a file can be verified using the `file` command from a terminal:
file -arch all -l /path/to/file
<!--
MT2xxx Linker
MT20xx Linker (general) errors
-->
<h3><aname="MT2001"/>MT2001 Could not link assemblies</h3>
<h3><aname="MT2002"/>MT2002 Can not resolve reference: *</h3>
<h3><aname="MT2003"/>MT2003 Option '*' will be ignored since linking is disabled</h3>
<h3><aname="MT2004"/>MT2004 Extra linker definitions file '*' could not be located.</h3>
<h3><aname="MT2005"/>MT2005 Definitions from '*' could not be parsed.</h3>
<h3><aname="MT2006"/>MT2006: Can not load mscorlib.dll from: *. Please reinstall Xamarin.iOS.</h3>
This generally indicates that there is a problem with your Xamarin.iOS installation. Please try reinstalling Xamarin.iOS.
<!--- 2007 used by mmp -->
<!--- 2009 used by mmp -->
<h3><aname="MT2010"/>MT2010: Unknown HttpMessageHandler `*`. Valid values are HttpClientHandler (default), CFNetworkHandler or NSUrlSessionHandler</h3>
<h3><aname="MT2011"/>MT2011: Unknown TlsProvider `*`. Valid values are default, legacy or appletls.</h3>
Something unexpected occured when trying to optimize generated binding code. The element causing the issue is named in the error message. In order to fix this issue the assembly named (or containing the type or method named) will need to be provided in a [bug report](http://bugzilla.xamarin.com) along with a complete build log with verbosity enabled (i.e. `-v -v -v -v` in the **Additional mtouch arguments**).
<h3><aname="MT3001"/>MT3001 Could not AOT the assembly '*'</h3>
This generally indicates a bug in the AOT compiler. Please file a bug [http://bugzilla.xamarin.com](https://bugzilla.xamarin.com/enter_bug.cgi?product=iOS) with a project that can be used to reproduce the error.
Sometimes it's possible to work around this by disabling incremental builds in the project's iOS Build option (but it's still a bug, so please report it anyways).
<h3><aname="MT3002"/>MT3002 AOT restriction: Method '*' must be static since it is decorated with [MonoPInvokeCallback]. See http://ios.xamarin.com/Documentation/Limitations#Reverse_Callbacks # this error message comes from the AOT compiler</h3>
<h3><aname="MT3003"/>MT3003 Conflicting --debug and --llvm options. Soft-debugging is disabled.</h3>
Debugging is not supported when LLVM is enabled. If you need to debug the app, disable LLVM first.
<h3><aname="MT3004"/>MT3004 Could not AOT the assembly '*' because it doesn't exist.</h3>
<h3><aname="MT3005"/>MT3005 The dependency '*' of the assembly '*' was not found. Please review the project's references.</h3>
This typically occurs when an assembly references another version of a platform assembly (usually the .NET 4 version of mscorlib.dll).
This is not supported, and may not build or execute properly (the assembly may use API from the .NET 4 version of mscorlib.dll that the Xamarin.iOS version does not have).
<h3><aname="MT3006"/>MT3006 Could not compute a complete dependency map for the project. This will result in slower build times because Xamarin.iOS can't properly detect what needs to be rebuilt (and what does not need to be rebuilt). Please review previous warnings for more details.</h3>
build or execute properly (the assembly may use API from the .NET 4 version of mscorlib.dll that the Xamarin.iOS version does not have).
<h3><aname="MT3007"/>MT3007: Debug info files (*.mdb) will not be loaded when llvm is enabled.</h3>
<h3><aname="MT3008"/>MT3008: Bitcode support requires the use of the LLVM AOT backend (--llvm)</h3>
Bitcode support requires the use of the LLVM AOT backend (--llvm).
Either disable Bitcode support or enable LLVM.
<!--
MT4xxx code generation
MT40xx main.m
-->
<h3><aname="MT4001"/>MT4001 The main template could not be expanded to `*`.</h3>
An error occurred when generating main.m. Please file a bug at http://bugzilla.xamarin.com.
<h3><aname="MT4002"/>MT4002 Failed to compile the generated code for P/Invoke methods. Please file a bug report at http://bugzilla.xamarin.com</h3>
Failed to compile the generated code for P/Invoke methods. Please file a bug report at [http://bugzilla.xamarin.com](https://bugzilla.xamarin.com/enter_bug.cgi?product=iOS).
<h3><aname="MT4101"/>MT4101 The registrar cannot build a signature for type `*`.</h3>
A type was found in exported API that the runtime doesn't know how to marshal to/from Objective-C.
If you believe Xamarin.iOS should support the type in question, please file an enhancement request at [http://bugzilla.xamarin.com](http://bugzilla.xamarin.com).
<h3><aname="MT4102"/>MT4102 The registrar found an invalid type `*` in signature for method `*`. Use `*` instead.</h3>
This currently only happens with one type: System.DateTime. Use the Objective-C equivalent (NSDate) instead.
<h3><aname="MT4103"/>MT4103 The registrar found an invalid type `*` in signature for method `*`: The type implements INativeObject, but does not have a constructor that takes two (IntPtr, bool) arguments</h3>
This occurs when the registrar encounter a type in a signature with the mentioned characteristics. The registrar might need to create new instances of the type, and in this case it requires a constructor with the (IntPtr, bool) signature - the first argument (IntPtr) specifies the managed handle, while the second if the caller hands over ownership of the native handle (if this value is false 'retain' will be called on the object).
<h3><aname="MT4104"/>MT4104 The registrar cannot marshal the return value for type `*` in signature for method `*`.</h3>
A type was found in exported API that the runtime doesn't know how to marshal to/from Objective-C.
If you believe Xamarin.iOS should support the type in question, please file an enhancement request at [http://bugzilla.xamarin.com](http://bugzilla.xamarin.com).
<h3><aname="MT4105"/>MT4105 The registrar cannot marshal the parameter of type `*` in signature for method `*`.</h3>
If you believe Xamarin.iOS should support the type in question, please file an enhancement request at [http://bugzilla.xamarin.com](http://bugzilla.xamarin.com).
<h3><aname="MT4106"/>MT4106 The registrar cannot marshal the return value for structure `*` in signature for method `*`.</h3>
A type was found in exported API that the runtime doesn't know how to marshal to/from Objective-C.
If you believe Xamarin.iOS should support the type in question, please file an enhancement request at [http://bugzilla.xamarin.com](http://bugzilla.xamarin.com).
<h3><aname="MT4107"/>MT4107 The registrar cannot marshal the parameter of type `*` in signature for method `+`.</h3>
A type was found in exported API that the runtime doesn't know how to marshal to/from Objective-C.
If you believe Xamarin.iOS should support the type in question, please file an enhancement request at [http://bugzilla.xamarin.com](http://bugzilla.xamarin.com).
<h3><aname="MT4108"/>MT4108 The registrar cannot get the ObjectiveC type for managed type `*`."</h3>
A type was found in exported API that the runtime doesn't know how to marshal to/from Objective-C.
If you believe Xamarin.iOS should support the type in question, please file an enhancement request at [http://bugzilla.xamarin.com](http://bugzilla.xamarin.com).
<h3><aname="MT4109"/>MT4109 Failed to compile the generated registrar code. Please file a bug report at http://bugzilla.xamarin.com</h3>
Failed to compile the generated code for the registrar. The build log will contain the output from the native compiler, explaining why the code isn't compiling.
This is always a bug in Xamarin.iOS; please file a bug report at [http://bugzilla.xamarin.com](http://bugzilla.xamarin.com) with your project or a test case.
<h3><aname="MT4110"/>MT4110 The registrar cannot marshal the out parameter of type `*` in signature for method `*`.</h3>
<h3><aname="MT4111"/>MT4111 The registrar cannot build a signature for type `*' in method `*`.</h3>
<h3><aname="MT4112"/>MT4112 The registrar found an invalid type `*`. Registering generic types with ObjectiveC is not supported, and may lead to random behavior and/or crashes (for backwards compatibility with older versions of Xamarin.iOS it is possible to ignore this error by passing --unsupported--enable-generics-in-registrar as an additional mtouch argument in the project's iOS Build options page. See http://docs.xamarin.com/guides/ios/advanced_topics/registrar for more information).</h3>
<h3><aname="MT4113"/>MT4113 The registrar found a generic method: '*.*'. Exporting generic methods is not supported, and will lead to random behavior and/or crashes.</h3>
<h3><aname="MT4114"/>MT4114 Unexpected error in the registrar for the method '*.*' - Please file a bug report at http://bugzilla.xamarin.com</h3>
<h3><aname="MT4116"/>MT4116 Could not register the assembly '*': *</h3>
<h3><aname="MT4117"/>MT4117 The registrar found a signature mismatch in the method '*.*' - the selector indicates the method takes * parameters, while the managed method has * parameters.</h3>
<h3><aname="MT4118"/>MT4118 Cannot register two managed types ('*' and '*') with the same native name ('*').</h3>
<h3><aname="MT4119"/>MT4119 Could not register the selector '*' of the member '*.*' because the selector is already registered on a different member.</h3>
<h3><aname="MT4120"/>MT4120 The registrar found an unknown field type '*' in field '*.*'. Please file a bug report at http://bugzilla.xamarin.com</h3>
<h3><aname="MT4121"/>MT4121 Cannot use GCC/G++ to compile the generated code from the static registrar when using the Accounts framework (the header files provided by Apple used during the compilation require Clang). Either use Clang (--compiler:clang) or the dynamic registrar (--registrar:dynamic).</h3>
<h3><aname="MT4122"/>MT4122 Cannot use the Clang compiler provided in the *.* SDK to compile the generated code from the static registrar when non-ASCII type names ('*') are present in the application. Either use GCC/G++ (--compiler:gcc|g++), the dynamic registrar (--registrar:dynamic) or a newer SDK.</h3>
<h3><aname="MT4123"/>MT4123 The type of the variadic parameter in the variadic function '*' must be System.IntPtr.</h3>
<h3><aname="MT4124"/>MT4124 Invalid * found on '*'. Please file a bug report at http://bugzilla.xamarin.com</h3>
<h3><aname="MT4125"/>MT4125 The registrar found an invalid type '*' in signature for method '*': The interface must have a Protocol attribute specifying its wrapper type.</h3>
<h3><aname="MT4126"/>MT4126 Cannot register two managed protocols ('*' and '*') with the same native name ('*').</h3>
<h3><aname="MT4127"/>MT4127 Cannot register more than one interface method for the method '*' (which is implementing '*').</h3>
<h3><aname="MT4128"/>MT4128 The registrar found an invalid generic parameter type '*' in the method '*'. The generic parameter must have an 'NSObject' constraint.</h3>
<h3><aname="MT4129"/>MT4129 The registrar found an invalid generic return type '*' in the method '*'. The generic return type must have an 'NSObject' constraint.</h3>
<h3><aname="MT4130"/>MT4130 The registrar cannot export static methods in generic classes ('*').</h3>
<h3><aname="MT4131"/>MT4131 The registrar cannot export static properties in generic classes ('*.*').</h3>
<h3><aname="MT4132"/>MT4132 The registrar found an invalid generic return type '*' in the property '*'. The return type must have an 'NSObject' constraint.</h3>
<h3><aname="MT4133"/>MT4133 Cannot construct an instance of the type '*' from Objective-C because the type is generic. [Runtime exception]</h3>
<h3><aname="MT4134"/>MT4134 Your application is using the '*' framework, which isn't included in the iOS SDK you're using to build your app (this framework was introduced in iOS *, while you're building with the iOS * SDK.) This configuration is only supported with the legacy registrar (pass --registrar:legacy as an additional mtouch argument in your project's iOS Build option to select). Alternatively select a newer SDK in your app's iOS Build options.</h3>
<h3><aname="MT4135"/>MT4135 The member '*.*' has an Export attribute that doesn't specify a selector. A selector is required.</h3>
<h3><aname="MT4136"/>MT4136 The registrar cannot marshal the parameter type '*' of the parameter '*' in the method '*.*'</h3>
<h3><aname="MT4138"/>MT4138 The registrar cannot marshal the property type '*' of the property '*.*'.</h3>
<h3><aname="MT4139"/>MT4139 The registrar cannot marshal the property type '*' of the property '*.*'. Properties with the [Connect] attribute must have a property type of NSObject (or a subclass of NSObject).</h3>
<h3><aname="MT4140"/>MT4140 The registrar found a signature mismatch in the method '*.*' - the selector indicates the variadic method takes * parameters, while the managed method has * parameters.</h3>
<h3><aname="MT4141"/>MT4141 Cannot register the selector '*' on the member '*' because Xamarin.iOS implicitly registers this selector.</h3>
This occurs when subclassing a framework type, and trying to implement a 'retain', 'release' or 'dealloc' method:
```
class MyNSObject : NSObject
{
[Export ("retain")]
new void Retain () {}
[Export ("release")]
new void Release () {}
[Export ("dealloc")]
new void Dealloc () {}
}
```
It is however possible to override these methods if the class isn't the first subclass of the framework type:
```
class MyNSObject : NSObject
{
}
class MyCustomNSObject : MyNSObject
{
[Export ("retain")]
new void Retain () {}
[Export ("release")]
new void Release () {}
[Export ("dealloc")]
new void Dealloc () {}
}
```
In this case Xamarin.iOS will override `retain`, `release` and `dealloc` on the `MyNSObject` class, and there is no conflict.
<h3><aname="MT4142"/>MT4142: Failed to register the type '*'.</h3>
<h3><aname="MT4143"/>MT4143: The ObjectiveC class '*' could not be registered, it does not seem to derive from any known ObjectiveC class (including NSObject).</h3>
<h3><aname="MT4144"/>MT4144: Cannot register the method '*' since it does not have an associated trampoline. Please file a bug report at http://bugzilla.xamarin.com.</h3>
<h3><aname="MT4145"/>MT4145: Invalid enum '*': enums with the [Native] attribute must have a underlying enum type of either 'long' or 'ulong'.</h3>
<!--- Not sure what happened to MT4146 -->
<h3><aname="MT4147"/>MT4147: Detected a protocol inheriting from the JSExport protocol while using the dynamic registrar. It is not possible to export protocols to JavaScriptCore dynamically; the static registrar must be used (add '--registrar:static to the additional mtouch arguments in the project's iOS Build options to select the static registrar).</h3>
<h3><aname="MT4148"/>MT4148: The registrar found a generic protocol: '*'. Exporting generic protocols is not supported.</h3>
<h3><aname="MT4149"/>MT4149: Cannot register the method '*.*' because the type of the first parameter ('*') does not match the category type ('*').</h3>
<h3><aname="MT4150"/>MT4150: Cannot register the type '*' because the Type property ('*') in its Category attribute does not inherit from NSObject.</h3>
<h3><aname="MT4151"/>MT4151: Cannot register the type '*' because the Type property in its Category attribute isn't set.</h3>
<h3><aname="MT4152"/>MT4152: Cannot register the type '*' as a category because it implements INativeObject or subclasses NSObject.</h3>
<h3><aname="MT4153"/>MT4153: Cannot register the type '*' as a category because it's generic.</h3>
<h3><aname="MT4154"/>MT4154: Cannot register the method '*' as a category method because it's generic.</h3>
<h3><aname="MT4155"/>MT4155: Cannot register the method '*' with the selector '*' as a category method on '*' because the Objective-C already has an implementation for this selector.</h3>
<h3><aname="MT4156"/>MT4156: Cannot register two categories ('*' and '*') with the same native name ('*').</h3>
<h3><aname="MT4157"/>MT4157: Cannot register the category method '*' because at least one parameter is required (and its type must match the category type '*')</h3>
<h3><aname="MT4158"/>MT4158: Cannot register the constructor * in the category * because constructors in categories are not supported.</h3>
<h3><aname="MT4159"/>MT4159: Cannot register the method '*' as a category method because category methods must be static.</h3>
<h3><aname="MT4160"/>MT4160: Invalid character '*' (*) found in selector '*' for '*'.</h3>
<h3><aname="MT4161"/>MT4161: The registrar found an unsupported structure '*': All fields in a structure must also be structures (field '*' with type '{2}' is not a structure).</h3>
The registrar found a structure with unsupported fields.
All fields in a structure that is exposed to Objective-C must also be structures (not classes).
<h3><aname="MT4162"/>MT4162: The type '*' (used as * {2}) is not available in ** (it was introduced in **)* Please build with a newer * SDK (usually done by using the most recent version of Xcode.</h3>
The registrar found a type which is not included in the current SDK.
Please upgrade Xcode.
<h3><aname="MT4163"/>MT4163: Internal error in the registrar (*). Please file a bug report at http://bugzilla.xamarin.com</h3>
This error indicates a bug in Xamarin.iOS. Please file a bug report at http://bugzilla.xamarin.com.
<h3><aname="MT4164"/>MT4164: Cannot export the property '*' because its selector '*' is an Objective-C keyword. Please use a different name.</h3>
The selector for the property in question is not a valid Objective-C identifer.
Please use a valid Objective-C identifier as selectors.
<h3><aname="MT5210"/>MT5210: Native linking failed, undefined symbol: *. Please verify that all the necessary frameworks have been referenced and native libraries are properly linked in.</h3>
This happens when the native linker cannot find a symbol that is referenced somewhere. There are several reasons this may happen:<ul>
<li>A third-party binding requires a framework, but the binding does not specify this in its <code>[LinkWith]</code> attribute. Solutions:
<ul>
<li>If you're the author of the third-party binding, or have access to its source, modify the binding's <code>[LinkWith]</code> attribute to include the framework it needs: <codeclass=" syntax brush-C#">[LinkWith ("mylib.a", Frameworks = "SystemConfiguration")]</code>
</li>
<li>If you can't modify the third-party binding, you can manually link with the required framework by passing <code>-gcc_flags '-framework SystemFramework'</code> to mtouch (this is done by modifying the additional mtouch arguments in the project's iOS Build options page. Remember that this must be done for every project configuration).</li>
</ul>
</li>
<li>In some cases a managed binding is composed of several native libraries, and all must be included in the bindings. It is possible to have more than one native library in each binding project, so the solution is to just add all the required native libraries to the binding project.</li>
<li>A managed binding refers to native symbols that don't exist in the native library.
This usually happens when a binding has existed for some time, and the native
code has been modified during that time so that a particular native class has
either been removed or renamed, while the binding has not been updated.</li>
<li>A P/Invoke refers to a native symbol that does not exist. Starting with Xamarin.iOS 7.4 an <ahref="#MT5214">MT5214</a> error will be reported for this case (see MT5214 for more information).</li>
<li>A third-party binding / library was built using C++, but the binding does not specify this in its <code>[LinkWith]</code> attribute. This is usually fairly easy to recognize, because the symbols have are mangled C++ symbols (one common example is <code>__ZNKSt9exception4whatEv</code>).
<ul>
<li>If you're the author of the third-party binding, or have access to its source, modify the binding's <code>[LinkWith]</code> attribute to set the <code>IsCxx</code> flag: <codeclass=" syntax brush-C#">[LinkWith ("mylib.a", IsCxx = true)]</code>
</li>
<li>If you can't modify the third-party binding, or you're linking manually with a third-party library, you can set the equivalent flag by passing <code>-cxx</code> to mtouch (this is done by modifying the additional mtouch arguments in the project's iOS Build options page. Remember that this must be done for every project configuration).
</li>
</ul>
</li>
</ul>
<h3><aname="MT5211"/>MT5211: Native linking failed, undefined Objective-C class: *. The symbol '*' could not be found in any of the libraries or frameworks linked with your application.</h3>
This happens when the native linker cannot find an Objective-C class that is referenced somewhere. There are several reasons this may happen: the same as for [MT5210](#MT5210) and in addition:<ul>
<li>
A third-party binding bound an Objective-C protocol, but did not annotate it with the <code>[Protocol]</code> attribute in its api definition. Solutions:
<ul>
<li>If you're the author of the third-party binding, or have access to its source, add the missing <code>[Protocol]</code> attribute:
<li>If you can't modify the third-party binding, build your project with the legacy static registrar by adding <code>--registrar:oldstatic</code> to the additional mtouch arguments in the project's iOS Build options page.
This happens when the native linker encounters duplicated symbols between all the native libraries. Following this error there may be one or more [MT5213](#MT5213) errors with the location for each occurrence of the symbol. Possible reasons for this error:
<ul>
<li>The same native library is included twice.</li>
<li>Two distinct native libraries happen to define the same symbols.</li>
<li>A native library is not correctly built, and contains the same symbol more than once.
You can confirm this by using the following set of commands from a terminal (replace i386 with x86_64/armv7/armv7s/arm64 according to which architecture you're building for):
<pre><code> # Native libraries are usually fat libraries, containing binary code for
# several architectures in the same file. First we extract the binary
<li>No <code>-gcc_flags</code> is passed to mtouch (in the additional mtouch arguments field of the project's iOS Build options).</li>
</ul>
</li>
<li>It's also possible to ask the linker directly to remove unused code by adding `-gcc_flags -dead_strip` to the additional mtouch arguments in the project's iOS Build options.</li>
</ul>
</li>
</ul>
<h3><aname="MT5213"/>MT5213: Duplicate symbol in: * (Location related to previous error)</h3>
This error is reported only together with [MT5212](#MT5212). Please see [MT5212](#MT5212) for more information.
<h3><aname="MT5214"/>MT5214 Native linking failed, undefined symbol: *. This symbol was referenced the managed member *. Please verify that all the necessary frameworks have been referenced and native libraries linked.</h3>
This error is reported when the managed code contains a P/Invoke to a native method that does not exist. For example:
```
using System.Runtime.InteropServices;
class MyImports {
[DllImport ("__Internal")]
public static extern void MyInexistentFunc ();
}
```
There are a few possible solutions:
- Remove the P/Invokes in question from the source code.
- Enable the managed linker for all assemblies (this is done in the project's iOS Build options, by setting "Linker Behavior" to "All assemblies"). This will effectively remove all the P/Invokes you don't use from the app (automatically, instead of manually like the previous point). The downside is that this will make your simulator builds somewhat slower, and it may break your app if it's using reflection - more information about the linker can be found [here](/guides/ios/advanced_topics/linker/) )
- Create a second native library which contains the missing native symbols. Note that this is merely a workaround (if you happen to try to call those functions, your app will crash).
<h3><aname="MT5215"/>MT5215: References to '*' might require additional -framework=XXX or -lXXX instructions to the native linker</h3>
This is a warning, indicating that a P/Invoke was detected to reference the library in question, but the app is not linking with it.
<h3><aname="MT5303"/>MT5303: Failed to generate the debug symbols (dSYM directory). Please review the build log.</h3>
An error occurred when running dsymutil on the final .app directory to create the debug symbols. Please review the build log to see dsymutil's output and see how it can be fixed.
<h3><aname="MT5304"/>MT5304: Failed to strip the final binary. Please review the build log.</h3>
An error occurred when running the 'strip' tool to remove debugging information from the application.
A security error ocurred while stripping debugging symbols from the application.
<!--
MT7xxx reserved
-->
<!--
MT8xxx runtime
MT800x misc
-->
<h3><aname="MT8001"/>MT8001 Version mismatch between the native Xamarin.iOS runtime and monotouch.dll. Please reinstall Xamarin.iOS.</h3>
<h3><aname="MT8002"/>MT8002 Could not find the method '*' in the type '*'.</h3>
<h3><aname="MT8003"/>MT8003 Failed to find the closed generic method '*' on the type '*'.</h3>
<h3><aname="MT8004"/>MT8004: Cannot create an instance of * for the native object 0x* (of type '*'), because another instance already exists for this native object (of type *).</h3>
<h3><aname="MT8005"/>MT8005: Wrapper type '*' is missing its native ObjectiveC class '*'.</h3>
<h3><aname="MT8006"/>MT8006: Failed to find the selector '*' on the type '*'</h3>
<h3><aname="MT8007"/>MT8007: Cannot get the method descriptor for the selector '*' on the type '*', because the selector does not correspond to a method</h3>
<h3><aname="MT8008"/>MT8008: The loaded version of Xamarin.iOS.dll was compiled for * bits, while the process is * bits. Please file a bug at http://bugzilla.xamarin.com.</h3>
This indicates something is wrong in the build process. Please file a bug at [http://bugzilla.xamarin.com](https://bugzilla.xamarin.com/enter_bug.cgi?product=iOS).
<h3><aname="MT8009"/>MT8009: Unable to locate the block to delegate conversion method for the method *.*'s parameter #*. Please file a bug at http://bugzilla.xamarin.com.</h3>
This indicates an API wasn't bound correctly. If this is an API exposed by Xamarin, please file a bug in our bugzilla ([http://bugzilla.xamarin.com](https://bugzilla.xamarin.com/enter_bug.cgi?product=iOS)), if it's a third-party binding, please contact the vendor.
<h3><aname="MT8010"/>MT8010: Native type size mismatch between Xamarin.[iOS|Mac].dll and the executing architecture. Xamarin.[iOS|Mac].dll was built for *-bit, while the current process is *-bit.</h3>
This indicates something is wrong in the build process. Please file a bug at [http://bugzilla.xamarin.com](https://bugzilla.xamarin.com/enter_bug.cgi?product=iOS).
<h3><aname="MT8011"/>MT8011: Unable to locate the delegate to block conversion attribute ([DelegateProxy]) for the return value for the method *.*. Please file a bug at http://bugzilla.xamarin.com.</h3>
Xamarin.iOS was unable to locate a required method at runtime (to convert a delegate to a block).
This usually indicates a bug in Xamarin.iOS; please file a bug at http://bugzilla.xamarin.com.
<h3><aname="MT8012"/>MT8012: Invalid DelegateProxyAttribute for the return value for the method *.*: DelegateType is null. Please file a bug at http://bugzilla.xamarin.com.</h3>
The DelegateProxy attribute for the method in question is invalid.
This usually indicates a bug in Xamarin.iOS; please file a bug at http://bugzilla.xamarin.com.
<h3><aname="MT8013"/>MT8013: Invalid DelegateProxyAttribute for the return value for the method *.*: DelegateType ({2}) specifies a type without a 'Handler' field. Please file a bug at http://bugzilla.xamarin.com.</h3>
The DelegateProxy attribute for the method in question is invalid.
This usually indicates a bug in Xamarin.iOS; please file a bug at http://bugzilla.xamarin.com.
<h3><aname="MT8014"/>MT8014: Invalid DelegateProxyAttribute for the return value for the method *.*: The DelegateType's ({2}) 'Handler' field is null. Please file a bug at http://bugzilla.xamarin.com.</h3>
The DelegateProxy attribute for the method in question is invalid.
This usually indicates a bug in Xamarin.iOS; please file a bug at http://bugzilla.xamarin.com.
<h3><aname="MT8015"/>MT8015: Invalid DelegateProxyAttribute for the return value for the method *.*: The DelegateType's ({2}) 'Handler' field is not a delegate, it's a *. Please file a bug at http://bugzilla.xamarin.com.</h3>
The DelegateProxy attribute for the method in question is invalid.
This usually indicates a bug in Xamarin.iOS; please file a bug at http://bugzilla.xamarin.com.
<h3><aname="MT8016"/>MT8016: Unable to convert delegate to block for the return value for the method *.*, because the input isn't a delegate, it's a *. Please file a bug at http://bugzilla.xamarin.com.</h3>
The DelegateProxy attribute for the method in question is invalid.
This usually indicates a bug in Xamarin.iOS; please file a bug at http://bugzilla.xamarin.com.
