4.7 Editor fails to start (fails to load one Blueprint)

Converted our project to 4.7 earlier today and now we cant load the project anymore.

Running it under the debugger shows that it happens inside this function:

UObject* ULinkerLoad::CreateExport( int32 Index )

where the following call returns NULL for the blueprint in question:

// Find the Archetype object for the one we are loading.
UObject* Template = GetArchetypeFromRequiredInfo(LoadClass, ThisParent, Export.ObjectName, Export.ObjectFlags);

Some more info regarding the Blueprint: Its our main character bp with a lengthy inheritance chain which goes like this:

ACharacter(Engine C++)<--AAbilityUser(Custom C++)<--OOMAbilityUser(Custom BP)<--OOMCharacter(Custom BP)

Any ideas?

Thanks in advance

I am getting this same crash in one of my levels. It’s happening to a non-character for me. (AActor<–ATreasureDispenser<–BP_TreasureDispenser<–BP_ChoppableTree).

The debug log is also outputting “Object ‘UserConstructionScript’ isn’t imported, because its outer is a placeholder” just before the crash.

I can load the level if I first open the file in the blueprint editor (I must do this everytime)

EDIT: I have a spawner class that populates the scene with this actor in the construction script. I also can’t open this blueprint class without crashing UNLESS I first load the class that is being spawned.