4.23.1 Window mode crash compiled game

Since 4.23.1 using DX11 will crash my compiled game if I switch to window mode. Switching to full screen mode works fine but switching to window mode will crash. I get this error after the crash…

LowLevelFatalError [File:Unknown] [Line:249] Result Failed at D:/Build/++UE4/Sync/Engine/Source/Runtime/Windows/D3D11RHI/Private/D3D11Viewport.cpp:368 with error DXGI_ERROR_INVALID_CALL

Is there any way this can be fixed in a hot fix patch for 4.23?. I have not tested 4.24 I would really prefer not to move my project over to 4.24 if I can avoid it.


We’ve recently made a switch to a new bug reporting method using a more structured form. Please visit the link below for more details and report the issue using the new Bug Submission Form. Feel free to continue to use this thread for community discussion around the issue.



Thank you, I’ll remember this for the future. I’ve actually decided to go to 4.24 with my project because I simply can’t reproduce the problem consistently, even in my own project. It will crash most of the time but then I can make some change and then it doesn’t crash, and then on the same build next time it does crash. I can’t seem to reproduce it in a clean project so I decided it’s probably not worth adding to the bugs list with something obscure like that. I kinda thought the error message might be all that’s needed but I don’t know and since I couldn’t reproduce it and there is already a new version of the engine that does work, it seemed a bit counter intuitive to report it there. My time spent fixing the small issues going to the new engine is much better spent like that I think anyway.

Thanks again, appreciate all you guys do.