An unexpected error condition occurred. Please [file a bug report](https://github.com/xamarin/xamarin-macios/issues/new) with as much information as possible, including:
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).
This usually indicates a bug in Xamarin.iOS/Xamarin.Mac; please [file a bug report](https://github.com/xamarin/xamarin-macios/issues/new) with a test case.
### <a name='BI0087'/>BI0087: Xamarin.Mac Classic binding projects are not supported anymore. Please upgrade the binding project to a Xamarin.Mac Unified binding project.
Xamarin.Mac does not support the Classic API anymore, because the Classic API is 32-bit only, and macOS 10.15+ does not support 32-bit applications.
The project must be [migrated to a Unified project](https://docs.microsoft.com/en-us/xamarin/cross-platform/macios/unified/updating-mac-apps) in order to support 64-bit.
### <a name='BI0088'/>BI0088: MonoTouch binding projects are not supported anymore. Please upgrade the binding project to a Xamarin.iOS (Unified) binding project.
MonoTouch is not supported anymore, because it only supports 32-bit.
The project must be [migrated to a Xamarin.iOS (Unified) project](https://docs.microsoft.com/en-us/xamarin/cross-platform/macios/unified/updating-ios-apps) in order to support 64-bit.
This usually indicates a bug in the binding generator; please file a new issue on [github](https://github.com/xamarin/xamarin-macios/issues/new) with a test case.
### <a name='BI1000/>'BI1000: Could not compile the generated API bindings.
This indicates a bug in Xamarin.iOS/Xamarin.Mac; please [submit an issue](https://github.com/xamarin/xamarin-macios/wiki/Submitting-Bugs-&-Suggestions).
### <a name='BI1014'/>BI1014: Unsupported type for Fields: * for '*'.
Please go to [[FieldAttribute]](https://developer.xamarin.com/guides/cross-platform/macios/binding/binding-types-reference/#FieldAttribute) documentation to see supported types.
### <a name='BI1028'/>BI1028: Internal sanity check failed, please file a bug report (https://github.com/xamarin/xamarin-macios/issues/new) with a test case.
### <a name='BI1031'/>BI1031: The [Target] attribute is not supported for the Unified API (found on the member '*.*'). For Objective-C categories, create an api definition interface with the [Category] attribute instead.
### <a name='BI1037'/>BI1037: The selector * on type * is found multiple times with both read only and write only versions, with no read/write version.
### <a name='BI1047'/>BI1047: Unsupported platform: *. Please file a bug report (https://github.com/xamarin/xamarin-macios/issues/new) with a test case.
### <a name='BI1051'/>BI1051: Internal error: Don't know how to get attributes for *. Please file a bug report (https://github.com/xamarin/xamarin-macios/issues/new) with a test case.
### <a name='BI1052'/>BI1052: Internal error: Could not find the type * in the assembly *. Please file a bug report (https://github.com/xamarin/xamarin-macios/issues/new) with a test case.
### <a name='BI1054'/>BI1054: Internal error: can't convert type '*' (unknown assembly). Please file a bug report (https://github.com/xamarin/xamarin-macios/issues/new) with a test case.
This usually indicates a bug in Xamarin.iOS/Xamarin.Mac; please [file a bug report](https://github.com/xamarin/xamarin-macios/issues/new) with a test case.
### <a name='BI1055'/>BI1055: Internal error: failed to convert type '*'. Please file a bug report (https://github.com/xamarin/xamarin-macios/issues/new) with a test case.
This usually indicates a bug in Xamarin.iOS/Xamarin.Mac; please [file a bug report](https://github.com/xamarin/xamarin-macios/issues/new) with a test case.
### <a name='BI1056'/>BI1056: Internal error: failed to instantiate mock attribute '*' (could not convert type constructor argument #*). Please file a bug report (https://github.com/xamarin/xamarin-macios/issues/new) with a test case.
This usually indicates a bug in Xamarin.iOS/Xamarin.Mac; please [file a bug report](https://github.com/xamarin/xamarin-macios/issues/new) with a test case.
### <a name='BI1057'/>BI1057: Internal error: failed to instantiate mock attribute '*' (could not convert constructor type #* (*)). Please file a bug report (https://github.com/xamarin/xamarin-macios/issues/new) with a test case.
This usually indicates a bug in Xamarin.iOS/Xamarin.Mac; please [file a bug report](https://github.com/xamarin/xamarin-macios/issues/new) with a test case.
### <a name='BI1058'/>BI1058: Internal error: could not find a constructor for the mock attribute '*'. Please file a bug report (https://github.com/xamarin/xamarin-macios/issues/new) with a test case.
This usually indicates a bug in Xamarin.iOS/Xamarin.Mac; please [file a bug report](https://github.com/xamarin/xamarin-macios/issues/new) with a test case.
### <a name='BI1060'/>BI1060: The * protocol is decorated with [Model], but not [BaseType]. Please verify that [Model] is relevant for this protocol; if so, add [BaseType] as well, otherwise remove [Model].
### <a name='BI1067'/>BI1067: The type '{type}' is trying to inline the property '{property}' from the protocols '{readonly.DeclaringType.FullName}' and '{writeonly.DeclaringType.FullName}', but the inlined properties don't share the same accessors ('{readonly}' is read-only, while '${writeonly}' is write-only).
### <a name='BI1068'/>BI1068: The type '{type}' is trying to inline the property '{property}' from the protocols '{protocol1}' and '{protocol2}', and the inlined properties use different selectors ({protocol1} uses '{selector1}', and {protocol2} uses '{selector2}.
### <a name='BI1069'/>BI1069: The type '{type}' is trying to inline the methods binding the selector '{selector}' from the protocols '{protocol1}' and '{protocol2}', using methods with different signatures ('{signature}' vs '{signature2}').
### <a name='BI1070'/>BI1070: The type '{type}' is trying to inline the property '{property}' from the protocols '{protocol1}' and '{protocol2}', but the inlined properties are of different types ('{property1}' is int, while '{property2}' is int).
### <a name='BI1071'/>BI1071: The BindAs type for the member "{type}.{member}" must be an array when the member's type is an array. See example binding below.
### <a name='BI1072'/>BI1072: Missing [CoreImageFilterProperty] attribute on {type} property {name}
This error happens when a binding type, decorated with `[CoreImageFilter]` attribute, has properties that are not decorated with a `[CoreImageFilterProperty]` attribute. E.g.
```csharp
[CoreImageFilter]
[BaseType (typeof (CIFilter))]
interface CICustomFilter {
CGAffineTransform Transform { get; }
}
```
To solve this error you need to tell the `CIFilter` key that you want to map to the property, e.g.
```csharp
[CoreImageFilter]
[BaseType (typeof (CIFilter))]
interface CICustomFilter {
[CoreImageFilterProperty ("inputTransform")]
CGAffineTransform Transform { get; }
}
```
If the property is inlined from a protocol then the `[Export]` value, prefixed with `input`, will be used by default. You can override this with by adding the `[CoreImageFilterProperty]` attribute (e.g. for `output*` keys).
### <a name='BI1108'/>BI1108: The [Protocolize] attribute is applied to the return type of the method *.*, but the return type (*) isn't a model and can thus not be protocolized. Please remove the [Protocolize] attribute.
### <a name='BI1113'/>BI1113: BaseType.Delegates were set but no properties could be found. Do ensure that the WrapAttribute is used on the right properties.
### <a name='BI1115'/>BI1115: The parameter '*' in the delegate '*' does not have a [CCallback] or [BlockCallback] attribute. Defaulting to [CCallback].
### <a name='BI1116'/>BI1116: The parameter '*' in the delegate '*' does not have a [CCallback] or [BlockCallback] attribute. Defaulting to [CCallback]. Declare a custom delegate instead of using System.Action / System.Func and add the attribute on the corresponding parameter.
### <a name='BI1117'/>BI1117: The member '*' is decorated with [Static] and its container class * is decorated with [Category] this leads to hard to use code. Please inline * into * class.
### <a name='BI1118'/>[NullAllowed] should not be used on methods, like '*', but only on properties, parameters and return values.
The `[NullAllowed]` attribute should not be allowed on methods but it could break existing binding projects.
Historically it was used on property setters. However using the attribute on _other_ methods can be misleading, e.g. should it apply to all parameters, the return value... and its presence/action can be misinterpreted in code reviews leading to binding bugs.
To fix this warning use the `[NullAllowed]` attribute only on parameters, properties or return values.