Don’t make it overcomplicated and don’t try to activate it in your Pawn’s constructor (It might not work if the pawn is still being constructed). Remove all of these and simply use BeginPlay or OnPosses in the AIController to run the behavior tree. But first, make sure that these events fire by printing a debug message. If they do, then check the behavior tree itself. It might be failing at the first decorator (if you have any) and hence not executing at all! If the issue still persists then please post a picture of your behavior tree itself along with the updated AIController blueprint.