https://bugs.winehq.org/show_bug.cgi?id=55979
--- Comment #2 from crashdance@charter.net --- As a further note, using thirds party Wine runners resolves the thread crashing issue. Specifically, I installed the Lutris Wine-GE runner from here:
https://github.com/GloriousEggroll/wine-ge-custom
Now the Battle.net launcher in the existing Wine prefix works successfully.