Looks like there was possibly a login issue where it couldn't successfully log you in. Did you possibly leave a window open and were away from your computer for a while?
What did you do to fix it? Did you submit the form on that page to describe what happened so our team can look into it?
Oops. Forgot to mention I was moving to Community Help since it is related to the site and not quitting.
Mark
EX Community Manager
chrome://settings/search#cookies In Chrome you can clear the cookies, it might help. I had it happen to me and I cleared the cookies and it worked.
If you have another browser it will have a different way to clear cookies.
Mark