Hello-
I just ran into trouble trying to finish the very first quest in the Sylvari personal story where you hunt the White Stag. In the opening of the quest, to track the Stag to a cave but find instead another Sylvari who is being attacked by Risen.
At the end of the mission, you bring the Sylvari to the mouth of the cave and are supposed to talk to him, but I was unable to do so. He was just standing there and the `F` key never went active on the screen to give talk as an option. This left me unable to complete the quest. I had to leave the instance and restart the mission, after which everything was fine.