Not sure if this has been posted elsewhere.
In the Underdark where the petrified Dark Elves are located you have the poison gas clouds, but the second one is where the problem lay. When I go to climb the vines I get tot he top and simply phase into the ground and slowly slide to the bottom of the chasm instantly killing any character that climbs it.
I had the same issue, compounded by it not allowing me to travel back to camp because one of my companions (the dead one), couldn't travel.
