I'm not able to repro it, but I don't have a mac box handy to test, I'll try and get a new build out soon that will hopefully fix some of these bugs.
Viewing post in Crashes upon selecting "championship"
...
loaded music[2: music/Vektor2089-Darband_Grand_Prix.ogg
sfx: 255
drawHUD: true
Error: unhandled exception: cannot read from file: assets/championships.json [IOError]
closing audio
sdl2 quit
Played through a handful of single courses this morning - super fun game!!! I'll surely be playing through all of the tracks, thanks for including this is The Bundle!