Can't select MIDI input
I'm using a Keystation 49 on MuseScore version 3.0.
My MIDI keyboard is recognized by Windows fine, but I am not able to select the "MIDI Input" Dropdown menu in the I/O tab in Preferences.
If it helps, this is happening in MidiEditor as well (keyboard is recognized but cannot be selected as input or output.
The keyboard is connected through a single USB port.
Comments
Be sure to connect and turn it on before starting MuseScore. Also be sure you have a 64-bit driver (assuming you are on a 64-bit system and using the 64-bit version of MuseScore, which is normally the default).