I just completed the quest Alduin's Bane. Serana was my follower at the time.
My problem is that during the fight with Alduin, Paarthurnax must have accidentally damaged Serana or vice versa, and now that the fight is over they are fighting each other.
I am playing on PC so I will be able to use console commands.
How should I go about fixing this? I tried selecting Serana and typing 'resetai' and 'disable'/'enable' but she continues attacking Paarthurnax.
Update: I temporarily fixed the issue by reducing Serana's health to 0 and then fast travelling elsewhere. I wasn't able to see what would happen when she got back up but I will leave this question up anyway as I suspect that there would be a cleaner solution using console commands.