I believe this has to do with a server configuration error regarding a redirection. When you enter
hitmanforum.com you're supposed to be redirected to
www.hitmanforums.com. It appends an additional slash though, so that you end up on
www.hitmanforum.com//. Discourse then though has a problem with that, notes a security error in the log and doesn't continue loading:
That's at least my observation. If you directly enter
there will be no redirection, thus you can access the site as normal.
I guess @ampburner might have to fix a configuration in the nginx redirection (or does Discourse do the redirection?).