This game never ceases to amaze me truly. I've don't this quest on probably 3 toons or so, decided to finish it up on another alt. I've never had this happen before but when Molag Bal lifts you into the air and after you beam him to death, instead of slowly falling to the ground, you get stuck midair. If you wait long enough, you're standing on invisible ground. You have no choice but to fall to your death. I think if you have around 21k health, you might be able to survive the fall damage. That's not the point really. After doing a little searching this quest has been exceptionally buggy for at least 4 years from the posts I found. Not even sure why I'm posting this as ZOS doesn't acknowledge anything. They might want to fix this with Greymoor around the corner and the influx of new players.