I have been having this weird glitch. Dexion keeps attacking everyone in fort dawnguard. As soon as I enter the fort, everyone comes and attacks him. He is essential so he doesn't die or anything but, I am still able to talk to him when he is downed. I either have to use the voice of the emperor, or get him down to talk to him. Any help would be appreciated.

I have the same problem

I'm pretty sure the problem is dexion doesn't spawn in the barrier so we never get the objective "defeat the entralled moth priest"

mabye

Fixxed it by reloading my save before entering forebear's hideout.

I Have tried that many times. I had no luck so i moved on with the quest. I hope bethesda fixes this.

It took me a few tries before it finally worked.

The problem is Serana, dismiss her before you go rescue the moth priest and it should work fine.