https://bugs.winehq.org/show_bug.cgi?id=51873
--- Comment #3 from Rémi Bernon rbernon@codeweavers.com --- Awesome, thanks!
Yes, joy.cpl is brittle and easy to crash, and I didn't spend much time trying to fix it (yet?).
For instance, I believe it's not properly checking the effect creation and assumes it succeeds as long as the effect type has been enumerated by EnumEffect / GetEffectInfo, even though it could fail depending on the effect parameters used. That may be what is happening for you.
It is also very possible that joy.cpl doesn't pass the correct effect parameters structure for effect types other than periodic. I could only really test it with periodic effects.
Regarding the buttons I considered raising the limit but then the layout was not very flexible. I'll have a look at your change, and see if we can maybe change the way it's presented to better support large number of buttons.