2 beta testers mentioned this fatal error for my game…

“[File:D:/Build/++UE4/Sync/Engine/Source/Runtime/Windows/D3D11RHI/Private/D3D11Util.cpp] [Line: 249] Result failed at D:/Build/++UE4/Sync/Engine/Source/Runtime/Windows/D3D11RHI/Private/D3D11Util.cpp:368 with error DXGI_ERROR_INVALID_CALL”

Specs for one of the testers machine is a Ryzen 7 2700, geforce 1060 with 16gb of memory and a mechanical hard drive running windows 10

This is occurring with a 4.23 version - 64bit packaged shipping product downloaded from Steam

Not sure if its a driver issue or missing re-distrib’s?

Any ideas on how to fix? Thank you.

I was able to recreate this error on an older laptop… so I tried creating shortcut and adding -DX12 after the exe, forcing it use DirectX12 and it WORKS!

However… is there anyway to detect this error in the engine and seemlessly force it to use Directx12 if necessary?

Since forcing users to use a separate way to start the game (after seeing if it crashes or not) seems very un-professional.

Also, why does DirectX11 not work on Some computers? (on my other computer the -DX12 fix doesnt work since I dont have DirectX12 on that computer)

More goofing around and I got it to work as long as Im in Windowed mode.

This might be some sort of bug in 4.23?

Perhaps some issue with computers using DirectX12 but forced to use DirectX11 while playing an unreal game built with version 4.23 doesn’t like fullscreen mode?

I say it that way because if I force it use DirectX12 using the -DX12 then it allows fullscreen fine.

And on computer that doesn’t have DirectX12 (and cannot use the -DX12 runtime param) it works fine in fullscreen

Is this a known issue (fullscreen mode) in version 4.23 that has been fixed in newer versions?

Did Anyone ever find the root cause of this/a verified fix, especially for systems which don’t support DX12.