I have been having problems and struggling to get on, but it was intermittent.
Has the reason for this been announced? Often when it is taken down there is a dump
While the reason is still a bit unclear, it is suspected that it was a DDOS-attack, which lead to some users being unable to access the forums / weren't able to browse the forum smoothly, but with huge laggs, delays, and timeouts, (me).
Theymos has announced a temporary fix for people still experiencing this issue, and it resolved my problems, see this pastebin,
https://pastebin.com/raw/EaKixQni