I've just played through the Knights of the Nine questline (for the sixth time) and I came across a weird bug. After beating the questline I went off and did other stuff for a few hours and came back to find that the priory was empty, all the NPCs vanished without a trace. Unfortunately I don't have a previous save that goes back far enough to the point that all of the NPC's are still in the game. I've gone out and explored the area around the priory and even went back to the place where you fight Umaril to see if they went back there for some reason. They were either killed while I was away or some kind of bug caused them to vanish out of the game. This is the first time I've ever come across this issue and was wondering if anyone else has had the same problem.