When using the latest Xess for Unreal Engine in 5.6.1 source, there is a fatal error whenever playing in the editor related to XessFG.

This is caputed in Visual Studio debug as ...

Despite supplying a pre-launch setting of:

[/Script/XeSSCore.XeSSSettings]
;stat XeFG - TO TEST COMMAND LINE
r.XeSS.Enabled=0
r.XeLL.Enabled=0
r.XeFG.Enabled=0
r.XeFG.OverrideSwapChain=1
bEnableXeSSInEditorViewports=False
r.XeSS.Experimental.PreExposure=1
r.XeSS.AutoExposure=1
r.XeSS.Supported=1
r.XeSS.Quality=2

A temporary fix for this is to handle the null value preventing the fatal error. Solution in the image below:

Replace the code at line ~147 with the below:

#if XEFG_ENABLE_IN_BP
if (XeFGRHI == nullptr)
{
FFrame::KismetExecutionMessage(TEXT("XeFGRHI is not initialized. Make sure Init() was called and XeFG is supported."), ELogVerbosity::Error);
return false; // or appropriate fallback
}
return XeFGRHI->IsXeFGSupported() && GetXeFGMode() == EXeFGMode::On && !XeFGRHI->IfGameViewportUsesXeFGSwapChain();
#else
return false;
#endif