I was trying to complete the Lord Errant quest. I reached the point where the battle with the controlled civilians starts and for reasons unknown to me, I was kicked from the game. When I managed to log back in, the battle was over, and I was prevented from both restarting it or moving on. There is no option to reset it so now I'm stuck and can't finish the quest. I had to teleport out from the instance area because it is a sealed off section.