I entered the Maelstrom Arena in vet, was able to fight the first round of the first stage, then the game suddenly freezes. The background sound still plays (cheering ppl).
Then I tried it a second time with less add-ons, but the game immediatly froze again after a few steps. So after that, I turned-off all addons, tried again with the same result.
The game froze.
Even tried to give up the quest and re-took it with the same result.