When Compiling most of my Blueprints in the latest 4.12.1 release version, the editor instantly crashes.
The Debugger shows this on top of the stack trace
UE4Editor_UnrealEd!FBlueprintEditorUtils::RefreshExternalBlueprintDependencyNodes() [d:\build\++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\kismet2\blueprinteditorutils.cpp:572]
This turns out to be the if statement in the following code:
UClass* OwnerClass = Struct->GetOwnerClass();
if (ensureMsgf(!OwnerClass->GetClass()->IsChildOf<UBlueprintGeneratedClass>() || OwnerClass->ClassGeneratedBy
, TEXT("Malformed Blueprint class (%s) - bad node dependency, unable to determine if the %s node (%s) should be refreshed or not. Currently compiling: %s")
, *OwnerClass->GetName()
, *Node->GetClass()->GetName()
, *Node->GetPathName()
, *Blueprint->GetName()) )
{
bShouldRefresh |= OwnerClass &&
(OwnerClass->IsChildOf(RefreshOnlyChild) || OwnerClass->GetAuthoritativeClass()->IsChildOf(RefreshOnlyChild));
}
After some investigation I found out, that the bug was caused by a OwnerClass holding a NullPointer. I successfully fixed the bug by changing it to the following (I only added a check to the if statement):
UClass* OwnerClass = Struct->GetOwnerClass();
if (OwnerClass && ensureMsgf(!OwnerClass->GetClass()->IsChildOf<UBlueprintGeneratedClass>() || OwnerClass->ClassGeneratedBy
, TEXT("Malformed Blueprint class (%s) - bad node dependency, unable to determine if the %s node (%s) should be refreshed or not. Currently compiling: %s")
, *OwnerClass->GetName()
, *Node->GetClass()->GetName()
, *Node->GetPathName()
, *Blueprint->GetName()) )
{
bShouldRefresh |= OwnerClass &&
(OwnerClass->IsChildOf(RefreshOnlyChild) || OwnerClass->GetAuthoritativeClass()->IsChildOf(RefreshOnlyChild));
}
I recompiled UE4 from Source and tested it and it works. The bug was causes by this Commit: https://github.com/EpicGames/UnrealEngine/commit/379dc42af86ad8320d383ce1fb76781ec8236b9b.
Unfortunately I’am not able to install an own version on every Computer in our Company, which means, we rely on the UE4 release versions. So please fix this as fast as possible and release a hotfix.