Remove "Enable MIDI input" option in Preferences
How to find the MIDI preference:
1. From the main menu choose Edit > Preferences...
2. Click on the Note Entry tab and notice the option "Enable MIDI input"
The preference offers little benefit to the user (a user can disable MIDI input from the toolbar). Instead, the preference means one extra thing that can go wrong (i.e. a user's MIDI keyboard stops working with MuseScore because the user accidentally unmarked the "Enable MIDI input" checkbox).
MuseScore should always support MIDI and the option to disable it should be removed from the preference window.
If the option to disable MIDI is needed for debugging or testing, keep it as a Command line option , where it is hidden from accidental use.