I had such a problem too, when I was about to play BW2. It occured because files on SD were corrupted I suppose. My SD slot in MacBook Pro is not working so I connected via my phone but on OS X I was unable to unplug it safely. I tried copying my backuped files via Windows and it worked nicely . Am I a gramma nazi? xD

Anyway I don't suppose it will help you. Maybe try to put fresh files on your SD? (of course leave save files )

This post has been edited by Rennossa, Mon, July 16th, 2012 at 09:31