I recently downloaded Musescore 2.1 on my Macbook (OSX 10.12.4). Strangely, there wasn't any sound when I clicked a note or playback. However, I have the same programme on my iMac (OSX 10.11.6) and everything works fine there.
Thereafter, I experimented downloading Musescore 1 on the macbook. To my surprise, things were working normally (i.e. there is playback sound!).
I would appreciate if someone could help me with this problem. I've tried to factory reset Musescore 2 / all the troubleshooting I could find in the forum to no avail.