I was wandering Solstheim west of the Skaal village when I found werebears and a madman fighting. I killed the werebears but then the madman talked to me. He told me the location of one of the Black Books which made him turn mad which was in the Telvanni Tower. The thing is that I already have all of the books and when I have the misc. quest for the book activated the quest marker points to my location on the map.

Has anyone come across this?

Why are so many Misc. quests jacked up? Anyhow, have you finished the main quest and beaten Miraak?

yes I have come across this same bug issue in every run/play thru of dragonborn.

Cept for the current run of dragonborn I just completed ~ why? because this is the only black book quest that ive been avoiding to do. Because I know that the same bug will prob get stuck in my journal again. Besides the reward from this particular black book isnt anything important that enhances my game imo.

All of the other quest bugs ive found a work around for minus this last book quest. Only way for me was to avoid that quest till a patch comes.

Yeah I beat the main quest.