Do you have a gold subscription? Im sure its just a server error. I'd try back again tomorrow. It is in its beta stages, though.
Yes I do, and yes I'll probably try again tomorrow.
EDIT: Oh no... I've figured out why its not working. I used my ubisoft account, yes, but my email wasn't linked to my gamertag. So basically, I'm done for, there's no possible way to log out of the account and it's been linked to my gamertag....