Was fighting the Barrow King boss and he falls through the floor and can’t get up. I see his crown poking through the floor, but you can’t fight him. Tried logging out for 5 minutes, but still under the floor.
So, I logged off for 2 hours, come back, he’s still under the floor. So I leave area, go 2 miles away, come back, he’s still under the floor. But, if you get up near the runic stone with the recipe, he follows and eventually can get back on ground level. If he falls through the floor again, go back to the stone.