So after looking through your sample the is specifically related to blueprints and circular references. KeyButton needs KeyActor, KeyPad needs KeyButton, and KeyActor needs KeyPad. There’s currently an outstanding with load/compile order that needs to be solved with Blueprints. I think they’ll be tackling it soon. In the mean time, you can solve your problem by ensuring that there’s no circular reference. You can do that with custom events, to notify up the chain what is happening.