, don’t know if it was , but bVxgiStoreEmittanceInFP16=true causes VXGI to stop working on all but 9xx cards I guess. Try setting it to false too. If you still have the build of NVidia, the sample project coming with it has setting once more in its own configurations.
And yea, the dbghelp.dll coming with UE4 is another, incompatible, one then what I have on my system too, and it doesn’t work. Maybe someone should make a support ticket for Epic about , I mentioned it in two bug reports but I didn’t had the feeling they looked at particular thing.