Hi folks. i think i found an explanation for the vampirelords at volkihar getting hostile to the player after being turned into a vampire and how mods affect this issue.. at first i don't use custom races and i know about the setrace commad, it doesn't help.. the problem is, there is a vanilla bug that makes a npc named rargal thrallmaster, and also two other npcs (look here at the bottom of the site http://www.uesp.net/wiki/Skyrim_talk:Bloodline) hostile for some reason (i have no idea why), if they "see" you turn into vampirelord-form. this also happens on the xbox, so its not related to any mods or custom races. and if one of these npcs is getting hostile, the rest of the vampires is joining the fight.. this seems to be affected by mods altering sneak values, in my case path of shadows. when turning into a vampire lord during harkons tutorial, these npcs are able to detect the transformation from the other rooms (because of altered detection range), without mod they can't. i can see them become hostile on the compass when looking towards the door while transforming the first time. an when they once became hostile, they stay hostile, and attack on sight as soon as the player leaves the room, as well as pulling every other vampire into th fight. so, if i play through this part with pos enabled, everyone is attacking me after the tutorial, without the mod, they stay friendly. as a little test i removed the gmst-records from the pathofshadows.esp with tesvsnip, and i was also able to play through this part with no issues. so, disabling sneak mods for the time of the tutorial should help the vampires getting hostile to the player, not turning into vl-form in volkihar after the tutorial also does (until this is fixed by bethesda or someone else) i don't know if i'm right, but this theory explains everything happening in my game. can somebody confirm this?