Steps to reproduce:

1. Open attached project "839333.zip"
2. Open scene "Dummy"
3. Build for Local Machine
4. Once building is done open solution with VS
5. Open App.xsml.cpp and at the end of constructor add "m_AppCallbacks->AddCommandLineArg("-force-d3d11-no-singlethreaded");"
6. Run solution as x86 Debug and notice that video does play
7. Run solution as x86 Release and notice error printed every frame:
InvalidOperationException: Nullable object must have a value.

-Plugin works fine on x86 when running Debug build. Doesn't work on Release and Master builds
-Reproducible on .NET and IL2CPP
-Tested on Universal 8.1 and plugin is missing in all cases
-Tested on x64, plugin is missing in all cases
-Running as Release throws the following error in UnityPlayer.log file:
Loading native plugins
Loading MFUnityBridge.dll
Failed to load 'MFUnityBridge.dll', expected x86 architecture, but was Unknown architecture. You must recompile your plugin for x86 architecture.

(Filename: C:\buildslave\unity\build\Runtime/Misc/Plugins.cpp Line: 139)

Reproduced with: 5.3.6p7, 5.4.1p4, 5.5.0b7