I get the same error when I try to compile the parent BP when a use its child BP as a child actor in a third BP…
e.g. I have a tank frame with a child actor component. This component will be set to a tank top bp. The tank top bps are all children of a tank top parent class. If I compile the tank top parent class when the child bp is referred as a child actor, the editor crashes with the error given by the op.
–kg