Close MIDI import panel
Windows 10, Musescore 3.6.487915773. Brand new installation.
Imported midi, saved as a Musescore file with mscz suffix.
The Close MIDI import panel's "X" is greyed out. [See x missing jpg]
However, on hovering in the place where the X should be, the button's frame appears. [See x button jpg]
The button works.
Not a big deal though, but for newbies this will be confusing.