Good evening (or morning) What error exactly? I don't see one posted in your question. Also, would highly recommend joining the Discord for Screeps there's a #world-help section that folks help people out in. Its a bit more dynamic and faster responses than the forums. I would say elif may be causing the issue if your doing JavaScript I'm not sure that works off-hand, looks like its a short for else if in python? Some people do play in python, there's a channel dedicated to it in the discord as well.