I’ve been trying to solve this issue. It appears to be similar to this post
I have an actor class that has a Uobject referenced. When I place this actor class into the scene in the editor, everything works fine. I can see what is supposed to occur. However, when I try to save the level, I get the error
"Can’t save …/…/…/…/…/Unreal Projects/BallsOut 4.8/Content/Levels/BallsOut_01.umap: Graph is linked to private object(s) in an external package.
Try to find the chain of references to that object (may take some time)?"
The Uobject is setup in the Actor class like so:
UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "mazeData") UMaze* theMaze = NewObject<UMaze>();
When I manually place the actor in the scene I can see “theMaze” in its properties box.