(Mac) Editor windows open on secondary monitor even when it's disconnected
When a secondary monitor is used to edit scores, the score window will open in the same area when MuseScore is restarted with the second monitor disconnected. As a result the score edit windows will be invisible.
The only remedy is to reconnect the second monitor.
This is an awkward bug: since my main computer is a laptop the secondary monitor is absent when I'm away from home and I can't edit any scores until I get back.
This can be worked around by repositioning the windows to the main monitor before quitting MuseScore, but that can only be done when the secondary monitor is still connected, not afterwards.