I had this issue twice this week, the forum was all locked up for me so I could reply to posts. If I log out I cannot log back in, the login screen does not load.
I tried from a totally different computer, somewhere else in the city, so not the same network or IP, but I got the same thing. The issue did solve by itself the first time after a day or two. Happened again today, for most part of the day, until just now.