We are using Unreal Engine 4.22.3 with DirectX12 as the default RHI to enable Real Time Ray Tracing for compatible Nvidia Graphics Cards.
This is possibly the cause of an launch error for some Nvidia GPUs including the 1080ti, 1050ti, and others.
Please try this fix if you are having this issue:
Steam -> Library
Right Click "Cine Tracer" -> Properties
Click "Set Launch Options"
Type -dx11
This resolves the issue for some people. I imagine this will disable the ability to use the Ray Tracing options on 10 series cards.
This is all new tech and the compatibility between UE4, Windows, Nvidia is changing every day.
Cheers,
Matt