All files on exchange are corrupt (this problem has been fixed)

Nobody is going to think you are using corrupted items. It's not a fault with your studio, at least wait it out and see if EA settles this. It's a shame to throw away all your work for nothing. Those that scan with Custard are going to see that everything is coming up corrupted when 'save file'ed.
Just because Custard is saying something is corrupted, doesn't mean it is - right now. I just hate to think about how disappointed you'll feel when they fix this and you've tossed perfectly good creations into the trash.