Playback is impossible and only results in creating an audio feedback loop
Playback simply is not working. Attempting to play a file - be it loaded or created in-session - inevitably results in playback either not starting or halting after a few seconds. The audio result is a sort of low-pitch pulsing noise akin to a feedback loop. After this is created, playback once again will not function. If playback had initially started but halted, the last one or two notes will stutter on and off at the same rate as the pulse. At least once, this issue has caused MuseScore to crash. The pulsing sound only stops after exiting the program.
This happens 100% of the time on Version 3.0.5 (for Mac). I have deleted and reinstalled Musescore 3.0.5 with the same effect. However, I did not experience this issue at all when I tried using Musescore 2.3.2, and have been using 3.0.5 on this computer for at least a month with no previous issues.
Comments
It's better to ask for help in the Support forums, as there are more people with experience to be able to diagnose problems. When you do so, I recommend you tell people what settings you see in Edit / Preferences / I/O, also try Help / Revert to Factory Settings. If it happens for all scores, including the default empty score after just adding a few notes, say so, but if it's specific to one score, please attach it.