To Reproduce:

1. Open the attached project, observe that, when it's loaded you'll get this error:

"FileNotFoundException: Could not load file or assembly 'UnityEditor.iOS.Extensions.Common, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies.
UnityEditor.EditorTestsRunner.EditorTestsRunnerWindow..cctor ()
Rethrow as TypeInitializationException: An exception was thrown by the type initializer for UnityEditor.EditorTestsRunner.EditorTestsRunnerWindow"

2. Try building it for iOS, building (not the whole editor) hangs up when building the first scene (last message in editor.log is the same error).
[This only seems to happen with development builds, it builds fine when using builds from katana, but you still get errors]

3. Open 'Editor/BuildResources.cs', if you remove '[InitializeOnLoadMethod]' or just:
'UnityEditor.iOS.BuildPipeline.collectResources += ..' it will no longer freeze.

This also BREAKS all user editor scripts (use the project ODR_Stripped_test.zip):

1. Open the attached project and ( DON't switch platform to iOS), but click AssetBundles/Settings to open a new Editor Window.
2. Switch Platform to iOS, you'll get the error.
4. Click anything in the custom window or just in the menu bar.
5. Observe that the custom menu buttons will disappear, and sometimes this will trigger a crash in Editor UI (below), but custom Editor scripts will no longer work properly in any case.