That’s strange (though I might be way off the mark!) – you don’t have a ‘customui’ folder in the ‘Moi’ folder
AppData > Roaming > Moi > customui
My ‘customui’ folder contains
Scripts.menu.htm
ScriptsFull.menu.htm
LightingOptions.htm
LightingPresets.menu.htm

I’ve just carried out a test: if I disable LightingOptions.htm and LightingPresets.menu.htm, I get the same empty rectangles as you.
That might be a lead – and I do mean might.