Assertion failed: bucket < NumBuckets

When I try to launch Unreal Engine editor using -DX12 I get this:

[2015.09.01-08.55.24:715][  0]LogWindows: === Critical error: ===
Fatal error: [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.9\Engine\Source\Runtime\RenderCore\Private\RenderingThread.cpp] [Line: 675] 
Rendering thread exception:
Assertion failed: bucket < NumBuckets [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.9\Engine\Source\Runtime\Windows\D3D12RHI\Private\D3D12StateCache.cpp] [Line: 145] 

which does not happen using DX11. I am using Windows 10 x64 + i5 4590 + 16Gb of RAM + GTX 970.

Thanks

Hi vinz243,

We are aware of issues with DirectX12. The active bug for this is UE-20622.

-.