Yes Thanks to the development team for their work. I had the same problem, I just haven't had time yet to sit down and try to recreate it. But philworthington's traceback is the same one i was getting.
I am having the same problem. We can log in on the new website so it isn't our username or password.
It worked fine Sunday which is why I suspect the change in the website to be the culprit.
Can anyone confirm this is the problem?