Not able to pick Free Week champions.

Not sure what is going on. Using an account in level 12 that has only 2 bought champions, trying to pick any champ other than those two results in a error message. "There was an problem selecting your champion. Please try again." This even occurs in practice mode with no one else. Many others in matchmaking seem to have the same problem.

EDIT: Bug has ended since the Free Champion rotation has been switched out.