Ok so this the Vaerminas quest you start in Dawnstar. I went in the door before the mage and now he dissapeared from the game and I can't advance through the quest unless I restart one hour back. Any help?

I'm guessing you had a companion with you? If so, you have to tell your companion tell stay before you first talk to the guy in the Inn. If you talk to the guy with an active companion or even if you tell your companion to stay by the door to the dungeon, the quest won't work.

Well the guy dissapeared from the world entirely and yes I did have a companion. If I get rid of my companion and then go back in does the quest work and the guy reappear?

I'm having this problem too, but I don't have any companions, I'm 100% certain on that. Anyone got any ideas?