Vez’okk refused to spawn after a 8 mask run which caused him to spawn before killing both minibosses in the valley of wisdom.
This seems to happen every run afterwards, basically bricking your character. It could be caused by the masks: multitude and nemesis as it seems to throw the mob count for that area completely out of whack.
Can we test things more than once before releasing things to live please?
I have the same issue - it seems the bonus objective for the Valley of Wisdom is not clearing properly between runs.
I have tried different combinations of masks - they don’t seem to be the issue.
Edit: I was able to fix it by tagging along with someone that didn’t have the problem. It showed incorrectly for me, but the boss spawned for the other person and we were able to kill it together. Since then it’s been spawning for me again too.
Same issue here, did 8 masks and went wisdom as a last zone, the miniboss wouldn’t spawn.
Thinking I have done something wrong, I have tried again, same issue but did wisdom as a 2nd zone cleared.
Then I tried going wisdom as a first zone 3 times (you can skip the elite if you hug the wall), twice killing the hulk first, then the shadowfiend thing, boss still did not spawn.
Tried taking off daredevil mask (lol there is only so much of that I can do in a day) and went 7 mask with wisdom as last zone, still not happening.
This is slightly annoying to say it politely.
Hey Blizzard, maybe some update?
I cannot finish this crap because of boss not spawning…
Fantastic!
What did it for me was a clue from the US-Forum. I tried it and it miraculously worked. 
I know this is only a workaround and it should happen but at least I was finally able to get a full clear again.
Also… Blizz get your s*it together… The In-Game Support doesn’t load.
Hi all,
Just wanted to note we have seen the reports of this and a hotfix is already in the works.
Hopefully shouldn’t be much longer now!
I don’t know if this is related, but for me the mob is spawning fine, only I’m not getting any black blood coagulate from one of the chests, think it’s the Valley of Wisdom one (first to the left of the main chest as you look at it).