Have you tried using the console? You can move Serana to you or you could just advance the quest stage directly. Hi yes i've tired every thing, f0rm setstage, ive repeated this and then waited a few hours , to advancing it, to teleporting Serana to fort dawnguard, to complely restarting it from where you have to go and speak to the leader of the dawnguard, i've cleaned the master file nothing seems to be working and i don't know what else to do, to save the game asi i've been play this play through for a number of years,, i really dont know what else to do i have tried everything you said and nothing is working when i prid serana she just casually strolls back to the vamprie castle, the setstage doesn't work, and i don't know what else to do, and more suggestions would be move welcome