I know, I messed up & should have checked the slack first. Now the chain will not move in the bar. Not by hand & not while running. The saw is a Stihl MS250 with 18" bar. I could go spend $100 for a new Stihl Light 04 bar and chain, but surely this has happened to someone else. My guess & 1st purchase would be a new chain, since it seems easier to damage. Can anyone that's been there, done that share their fix? I am a homeowner and just use it at home occasionally.