I see what you mean, if I use Tab key I can cycle through the various visible tabs but a certain point nothing is more highlighted and I guess it is blindly selecting something in the left tab I can't see on my screen.
Here is what MESS 0.215 looks on my Mac:

MESS 0.215 actual UI

As you can see the left tab is not shown at all, and I have of course enabled it in the configure panel.

Last edited by MacBox360; 11/21/19 10:13 PM.