https://bugs.winehq.org/show_bug.cgi?id=49590
--- Comment #8 from Maciej Stanczew maciej.stanczew+b@gmail.com ---
I might have just not tried enough times
Yup, that was it. Just now I launched Battle.net and then Diablo III, and I got 4 back to back Agent crashes, resulting in the popup appearing and the game being delayed from starting. (The 5th Agent didn't crash and the game finally launched after about 30 s of delay.)