I got it in Chrome as well, though a sister comment got it in safari. Any ideas on the cause? Would want to avoid this in the future.

The only exceptional thing about my account was that I'm a member of two dev programs, a business and an enterprise, on the same account.

I got this screen in Safari as well. Went to web inspector to clear cookies, but I was too slow :/

I got that at first, opened an incognito window and re-logged in and that appeared to have fixed it, perhaps sessions created from before the maintenance were broken?

http://i36.tinypic.com/2555m6a.png yeah me too!

I got that screen as well - I went over to safari and game over

Who designed that screen? Where's the fail whale?

Had two browsers open, got that error in both.