Thanks for your patience everyone!
The forum went down today starting at around 11:45 EST.
The reason it went down seems to be because the server ran out of storage space. Part of this is because the forum is growing pretty quickly, with nearly 100,000 people using it every week.
We cleared some space as a temporary fix, and plan to upgrade the server next week. So the forum may go down for a short while on Thursday, Feb 15.
Thanks again for your patience and understanding!