I was in the process of making a map, and using a command block to get player heads for decoration. Stupid me used a pressure plate to activate the command block, and after removing one ID but before putting in another, the cat (real one) bumped my elbow and the command block tried to 'give' me the Head With No Name. This caused a crash. I know this is what caused the crash, but I can get logs if it's really necessary. Since then, I have tried removing the command block with MCEdit, removing my player.dat (in case the Nameless One was in my inventory or something), and switching my level.dat with my level.dat_old (although the multiple attempts have probably made that pointless.) If someone can tell me how to keep it from trying to create this entity, I would be grateful. Failing that, at this point, I'm willing to settle for just saving the contents of the chest of (named, non-glitched) heads that I'd generated before the accident.