Hello, What have you done to narrow this down? You say this happens on random when you use copyover, You know copyover writes to descriptors right? Are you getting all of your normal messages that you normally see when doing a copyover? Are you doing a copyover with level 1 chars who can't save? They wouldn't have a player file yet if they can't save till level 2. That could cause the error you are recieving.
If you have double checked the copyover functions and they are correct, Then you need to look at what Rom normally loads during a reboot or copyover. Somewhere, During the boot up of your mud, A message is being writting about something that it can't find such as no playerfile, possibly trying to reload a link dead char, a fouled up mob or one of many other things. You may want to start looking at what is being loaded during the copyover recovery. I think this is a tough situation really and I don't see any easy way around it. Maybe look through db.c at what is getting loading and try to backtrack any changes or anything that could cause the error. My thoughts at the moment, Chris Bunting

