Ok so im a warewolf and dawnguard so I cant become a vampire.....WRONG! the 100% resist thing is apparently bugged! I dident know i had vamp till it already was past taking a potion only because when i went in the sun the message poped up! i though ohh man wtf! am i not a warewolf anymore? but no im a warewolf AND a vampire! i dident want to be a vampire so i said screw it ill just cure it grabed one of the many black soul gems i have in one of my houses and went to start the quest to my suprise I CANT START THE QUEST! no one gives me a lead or quest the dude wont talk to me about being a vampire NOTHING my guess is because im a warewolf and im not supose to be able to be a vampire it gliched but i went though the stages of vamp and though well if i have to live with it i need to feed so i dont hit stage 4 and get attacked everywhere i go! and BOOM CANT EVEN FEED!!!!!!! so i get vamp even though im a wolf and have 100% res somhow and cant get rid of it and cant feed to keep it at bay......had to reload my save that wasent the auto save i had when i first started playing thismorning LUCKLY i only lost 6 hours of play time went from lvl 61 to lvl 58 lost all the upgraded dragon armor i made and lost the dragon bones and plants i had farmed all day and lost the last 30 levels of alchamy i had done today....but its better then losing all 120 hours of play time on that dude o.O

The resistance being bugged has been known forever now. Although this is the first I've heard of contacting vampirism while as a werewolf because of the bugged resistance.

But it makes sense that you can't feed. Papyrus is obviously confused, and hasn't changed the flag.

Yes i would suggest to load a previous save too. !!!!!

And after that clear your cache too...