So well, as I could not log in through forums, i had to login just by Account Management website and then clicked Forums button… here is what error appears when i tried to log in through forums:
Login Error: Portal returned error: 42: {"error":42,module,line,“text”:"ErrTimeout"} — /var/www/forum/gw2/en/shared/bundle/ruby/1.9.1/gems/oauth2-0.8.0/lib/oauth2/client.rb:108:in `request’ — login_controller.rb 94 (fangamer:-1).