I noticed this as well while experimenting. I had converted one of my models to PBR materials but couldn't figure out why the wings were fine but the fuselage was much darker. Turned out the base material for the wings was set for 255, 255, 255, but the fuselage was something like 150, 150, 150.
Hi Arno, is the "check for updates" function working? I know there have been several updates to MCX recently, but I've not had the "update available" prompt when starting MCX recently.
Both "CheckForUpdateAtStartUp" and "CheckForUpdateUnstable" are set to "true" in options.