I keep getting this error when I try to click notifications, inbox, bookmarks, or account options. Yesterday when it started I would also randomly get it while typing instead of the "Draft saved" message.
Its intermittent, and I haven't seen a pattern to it yet. It usually seems to clear up if I change pages a few times, but sometimes while I'm getting it I'll also start getting this, which sometimes leads to me appearing to be logged out (but not actually being logged out).
Error 503 Service Unavailable
Varnish cache server
When I went to a forum and then clicked it, it worked and then backing out to the main page it was working.
The others were working, notifications, inbox and options.
I also had it act like I was logged out on the sub-forums but still showing as logged in on the main page.
It's like it just isn't checking our credentials; as if that service were timing out, but I would expect that to correlate with a lag in page loads, and I haven't noticed any delays there.