I've been working on an engine for a while now, and everything seems to work (thrust, effects, gimbal, etc) except when I place it in the editor. When I try to pick it up again (to move or delete or whatever), it doesn't light up like a part usually would, and I can't pick it up. Is this a common problem? I wasn't able to find it on the forums, so if somebody can help me I would really appreciate it.