So this usually happens if the user doesn't enter a valid domain when signing in (bad UX, need to fix that).
I don't know what would have caused it in this situation, but if you click out of the dialogs (there definitely might be quite a few...probably like 4 or 5) then go to Profile->Settings and remove the account, you should be able to sign back in.
Can you try that and get back? I don't actually know what would have caused that to happen though...I can see there isn't a host there though for the selected account, so I'm pretty sure something happened to the host.