Kerbal Space Program

I wanted to add my insight from years of experience: I think this is likely a hardware issue.

This looks like either video memory overheat, or GPU overheat.

You may want to check your power management settings to see if you can turn on active cooling while you are playing. You could also try throttling back your processor's maximum speed by one notch to reduce the amount of heat being fed into the unified heat sink from the processor, allowing it to better cool your video components.

It seems some games handle this better than others. There is a routine to reduce this issue. (Checksumming and/or reloading of textures and shaders in certain cycles.)

You might want to throwing together a large rocket or airplane (or simply try loading someone's wiggler) and see if that will get it to trigger in stock.

Otherwise it would be helpful to figure out what add on is causing it. I suspect it may be B9 Aerospace since that is most likely to increase the number of physics calculations.

Make sure to report back, since that information could be very helpful.