the blind beast didn't drop the passive book

The Blind Beast icon is appearing gray, but the book didn't drop. I'm in the endgame with 24 weapon set points.

It's probably a bug; I've seen other people reporting the same problem. I checked all the bosses that drop the book, and I didn't miss any.

The beast doesn't drop the book anymore. This isn't a bug. This is you not reading the patch notes.

You get the passives from the Dark Mists quest as of 0.4