im currently in the last cavern in the forebears' holdout. i've killed all the dawnguard but i still cant free the moth priest. i understand that i need to search malkus for the weystone source but it's not on him. i've searched every other body as well, nothing. when i empty out malkus's body, the game doesnt display the "Empty" sign it usually would when a container or NPC doesnt have anymore items, so this might be one of the game/dlc 's many bugs/glitches. am i the only one with this problem? is there anyone that has a solution? i recommend bethesda to play their [censored] at least 3 times before releasing it.

Have you tried Loading your Auto-Save from the entrance and trying again?

That seems like the obvious path to take. If that doesn't work, then try loading a Save from before you entered the cave.

Try interacting with the holder thing anyway, it might have done the invisible in inventory bug.

I just had this bug and I even tried dismissing Serena in case it is some sort of follower bug... no avail. Come on bethesda is this for real?

HA! I found the answer! Hit the tilde key and type this when you get stuck! Use the console command setstage DLC1VQ03Vampire 70 to progress.