Here's a solution someone posted on t3fun
Quote
Hey, I've found a way to more or less fix the "You've been disconnected" or "Error: Unknown error from server" errors upon logging in. Just try to remove (or move somewhere else) the folder with your character's name in \Users\YOUR_PROFILE\Documents\My Games\Hellgate\Save\Multiplayer and then log in, you should be able to get in. It's not 100% guaranteed though.
Of course it's not 100% guaranteed. Shit doesn't work.
This post was edited by Vicc on Jul 2 2011 06:28pm