I wish I knew how to quit you.
When I quit MuseScore 3 by selecting MuseScore in the upper left corner of my screen, then choosing "Quit MuseScore", my computer tells me that MuseScore "quit unexpectedly". Is there a better or different way to shut down MuseScore? I am using MacOS Sierra 10.12.6 and Safari 12.0.3, and I am new to MuseScore (and music writing software, in general). But, I am working my way through the online course.