Problem Mesh randomly changes brightness

[Arthur Dent]

Hi Everyone

I'm working on some kind of Mobile Service Tower for a rocket of mine.
The tower itself is spacecraft.dll based.

However, the brightness of the mesh changes randomly in Orbiter. Sometimes, it changes once a second, sometimes every three seconds. When I pause the simulation, the effect doesn't occur. I've already tried it without a texture and/or with a different material. So far I had no luck.

Any Ideas or suggestions?

 

[Artlav]

Where is the COG of the tower vessel (yellow square)? If it's near the ground, try raising it.

 

[Arthur Dent]

The COG was 0. I changed it to 0.01 and now it works just fine!

Thanks a lot Artlav!