Just in case it happens to anyone else, I tried to log in after the unscheduled maintenance today and got the dreaded 103 error - firstly for "incorrect login credentials", and then it morphed into "your account classification does not allow you access to the server at this time. Please contact Support (etc)." (Which is obviously wrong, since I've been playing since the 30th and have the digital imperial edition with the 5 day early access).
Re-entering my password didn't work, but deleting my saved username in the top field of the login form, and re-entering it manually, worked.
I'm guessing the servers are under stress now the 3 day early access has begun.