On the 'PROPHET' questline in Dawnguard, having sucessfully released Dexion Evicus he heads back to Castle Dawnguard but on arrival everyone tries to kill him. Although you can still speak to him he just writhes around on the floor when you ask him to read the Elder Scroll?
Tried re-loading to a couple of past saves but still always the same outcome.
If you don't have any spells strong enough to Pacify the Dawnguard you could try leaving the area for over three in-game days the area reset usually calms them down. It sounds like this (and Dexion being the one attacking instead) could be somehow caused by taking Serana in to Forebears' Holdout with you and maybe the Vampires attacking Dexion while he's in the shield.
Blue text in a comment is a link to a wiki page so the word Pacify was a link to the spells page, blue text with a small white arrow is a link to an outside web site (so with those maybe hover the mouse over them to see where they go before clicking).
For those spells to stand a chance of working you probably would of had to of put some work in to the Illusion skill though.
Having gone through this twice, you need to rescue the priest alone. If you take Serena in with you, he will attack her and going back to the Dawn guard, everyone will attack him. Taking a vampire in to rescue the priest adds the bug.
Levelled up in Illusion and gave the Pacify spell a try, no good unfortunately :( Also tried healing him but he justs starts trying to fight you again. This massively sucks. Played loads of quests since this bug so no chance of re-loading a save point.
Is there any way you can re-start the Dawnguard questline without altering your main game?
He will level with you up to level fourty so you may need to duel cast the spell, i didn't notice before but your on the PC so you could try opening the console clicking on Dexion and trying one of the commands -
setav aggression 0
addfac 0005A1A4 1
There is a command to restart a quest but it's not very reliable (so only as a last resort) -
126.96.36.199 wrote: Having gone through this twice, you need to rescue the priest alone. If you take Serena in with you, he will attack her and going back to the Dawn guard, everyone will attack him. Taking a vampire in to rescue the priest adds the bug.
Dom TSD wrote: Although you can still speak to him he just writhes around on the floor when you ask him to read the Elder Scroll?
I took Serana to the rescue him too and he attacks everyone in the Dawnguard everytime I arrive in the castle too but he still read the scroll so I doubt this is the solution.
I tried another way, trough finding out which stage I was at in the quest, then setting myself to a higher stage so the quest would be complete. If like me, your problem is that you don't have the option to talk about the elder scroll follow the instructiobs on this site. Nothing helped for me but this did. (IMPORTANT: Must be on PC because you need console command)
The bug arises, due to the Moth pries being enslaved by the vampire and your companion attacking him, before you get the quest of defeating the enslaved Moth priest.
If you bring Serana or Lydia does not matter. Defeat the vampires, go to the place where you can inactivate the barrier and inactivate it, making sure that neither you or your companion attack the priest, before you get the quest update, then you should be fine.