Fixes #6539 (#6969)

Xamarin.Forms.Platform.iOS/Renderers/PageRenderer.cs

@@ -207,7 +207,7 @@ namespace Xamarin.Forms.Platform.iOS
 			if (NativeView == null)
 				return;
 
-			var uiTapGestureRecognizer = new UITapGestureRecognizer(a => NativeView.EndEditing(true));
+			var uiTapGestureRecognizer = new UITapGestureRecognizer(a => NativeView?.EndEditing(true));
 
 			uiTapGestureRecognizer.ShouldRecognizeSimultaneously = (recognizer, gestureRecognizer) => true;
 			uiTapGestureRecognizer.ShouldReceiveTouch = OnShouldReceiveTouch;