You didn't pay attention while copying a game save
what's that have to do with DLC? If you did manage to delete all your downloaded content the only thing I can think of is removing everything from skate 3 before you enter the save data which doesn't support the idea of copying game saves if you did ACTUALLY buy this stuff just go download it again and do the career again I've done the career several times on other accounts as said not hard actually kinda fun if you're into the contests and such and if not well you don't need all that stuff to enjoy it that's the best part you can hop in, decline the first mission and start exploring it's not like you're restricted like tony hawk no area location unlocks needed to skate around It might be on principle but whatever dude you made a mistake get over it and start playing again because there's no telling how long the servers will last with minimal to no support