Crash in FWidgetBlueprintCompilerContext::FinishCompilingClass

Hey,

We’re experiencing this crash when running the editor with -server.

GetWidgetTreeArchetype seems to be returning nullptr for an editor utility widget and it’s not clear why.

Can you offer any insights into what this might be and how we can remedy it?

Cheers!

Hello [mention removed]​,

I wasn’t able to reproduce the crash locally on a fresh UE5.5 project using -server or PIE with a dedicated server.

Looking at the source code, the crash appears to occur in this section:

UWidgetTree* Tree = NamedSlotClass->GetWidgetTreeArchetype();
TArray<FName> SlotNames;
Tree->GetSlotNames(SlotNames);

If Tree is nullptr here then it would explain the access violation. However, in my tests, this method is called when compiling the Editor Utility Widget, and I wasn’t able to get a nullptr from GetWidgetTreeArchetype().

Could you provide a minimal reproducible project where the crash happens or at least more detailed repro steps?

Best,

Francisco