Hi
I think I wrecked the vampire power mechanic in season 2.
For faster power upgrading I leveled always the first suggested selection of power. It worked until there were no more powers to select in the top (although 4 powers still locked). Progress bar in the middle says “!! Missing!! - -1:Name” and at the bottom of the description it says "!! Missing!! - -1:Description.
I already restarted the game, I changed game language, but nothing worked.
So at the moment I am not able to unlock and upgrade four of my vampire powers. Two of them would be very interesting for an additional build and I dont want to start a new character.
Maybe an official Blizzard guy can communicate my issue.
Thanks.
Some of the vampire powers come from other sources than Potent Blood unlocks. A couple come from the Vampire Hunter task board, and some from season or other quests.
Yeah, I got that and realised I had to do the season quest for the last ones.
Only 3 powers to go 
Great hint. You were rigth. I follow the quest line and enabled one of my locked powers. So I think it will be the same for the rest. Finaly an explaining hint in the power update window would have been helpful.
Thank you.