This locking-out thing happened to me, too--I'd nominated under both Marvel - TV and Marvel Cinematic Universe, and now I can't edit anything because the system says, "You seem to be trying to nominate Marvel Cinematic Universe more than once." It's okay in my case--I was just going to play around with some more freeforms--but I thought I'd confirm that it's a weird bug that apparently pops up with the Marvel split.