Reproduction steps:

1. Open the attached project with Unity 5.4
2. Run the only scene in the project
3. The scene contains one script, which basically changes AA in OnGUI method
4. If editor doesn't crash after starting the scene, try to change AA several times by pressing GUI buttons in the top left corner
5. Eventually it will crash with the following stack trace:

========== OUTPUTING STACK TRACE ==================

0x00007FFC2CC42D46 (d3d11) CreateDirect3D11SurfaceFromDXGISurface
0x000000014143ABBA (Unity) GetActiveRenderTargetCountD3D11
0x000000014143AEE1 (Unity) SetRenderTargetD3D11
0x00000001414313B0 (Unity) GfxDeviceD3D11Base::SetRenderTargets
0x0000000141459990 (Unity) GfxDeviceWorker::RunCommand
0x000000014145ED6F (Unity) GfxDeviceWorker::Run
0x0000000141456D9D (Unity) GfxDeviceWorker::RunGfxDeviceWorker
0x000000014058E9B8 (Unity) Thread::RunThreadWrapper
0x00007FFC307A8102 (KERNEL32) BaseThreadInitThunk

========== END OF STACKTRACE ===========

Reproduction gif: https://gyazo.com/00f9efe9edb29bee7abca9720c5eefdc

Reproducible with 5.4 only (tried Beta 9 and Beta 15).
Not reproducible with 5.1, 5.2 and 5.3

DirectX9: Crashes immediately after pressing Play button
DirectX11: Crashes after changing AA several times
DirectX12: Couldn't get a crash, because game view is black after pressing Play

Note, that there is no crash on standalone, instead there is a big performance drop.