Not Recognized As A Vampire
This is often caused by using a custom race instead of one of the original races. If you are using a custom race it may not have the appropriate flags set to identify you as a vampire. For example, my Nord Vampire is of the race "NordRaceVampire" and has the keywords "ActorTypeNPC", "ActorTypeUndead", and "Vampire" attached to it – you can check this in the Creation Kit. Please contact the author of your custom race mod for more help.
You can now use my Mod Configuration Menu (STATUS page) to check if you have the appropriate flags on your character.
The author of any custom race can easily make a vampire version of their race (or you can too if you are so inclined):
1) Load the custom race .esp in the Creation Kit
2) Open the custom race (i.e. look for LunariRace)
3) Change the ID of the race to "yourcustomracenameVampire" (i.e. LunariRaceVampire)
4) Change the name of the race to "yourcustomracename Vampire" (i.e. Lunari Vampire)
5) Save this as a new race, don't overwrite the original
6) Open up the race you just created
7) Add the keywords "Vampire", "ActorTypeNPC", and "ActorTypeUndead" to your new race (General Data, under Keywords)
8 ) Add the spells "VampireHuntersSight", "VampirePoisonResist", and "VampireVampirism" to your new race (General Data, under Specials)
9) Save your new race
10) Save your custom race .esp and exit the Creation Kit
After this, you can use the console to "setrace yourcustomracenameVampire" (i.e. setrace LunariRaceVampire) and you'll be able to feed normally and be identified as a vampire in the game.
NOTE: Be sure you use my menu option to infect yourself with Sanguinare Vampiris and rest 3 days so you have all the vampire perks and scripts running in the background. You cannot just change your race, you have to have the PlayerVampireQuest script running in the background too!
To cure yourself, use my menu to reset vampirism, cure your disease before 3 days are up, and use the console to "setrace yourcustomracename" (i.e. setrace LunariRace).