So I am about halfway through the Dawnguard quest line - I have just rescued Florentius and was returning to Fort Dawnguard with the Exploding Firebolt Schematic, but the whole Fort is hostile to me .

Is this a glitch, or did I do something wrong?

Thanks for any insight!

did you accidentally hit florentius?
Edit: should probably put this in the dawnguard section

Sorry! Posted here by mistake.