Enthir in winterhold will not sell to me I have only the option of asking whats not allowed here and that is all! When I click that btw nothing happens,If a fix does happen will it be able to fix him on my existing save? Also many other people have this same problem around 30-40% I would say.

He has to be in his chambers to get the option to buy from him

I'm having the same problem. The wiki says it's a bug if you don't barter with him before becoming Arch Mage.

in the quest discerning the transmudane i inscribed the lexicon and went back the signus but he wont give me the part of geting the blood. if you can help message xRaidenRISINGx i am on almost every day.