2nd image shows a red cube textured using the Automotive Materials car paint. The top image is what happed when I applied car paint to the pickup truck. In fact, everything in the car paint folder stopped working resulting in red text error messages if you opened up the car paint file as shown in the bottom image.
It’s the Automotive Materials Package itself. It the car paints work, the metals, glass and interior materials don’t and vice versa. It depends on what you use first.
I purchased one of the cheaper “car paint” packs from Marketplace and downloaded the massive free twinmotion materials package for metals, rubber, plastics and glass for use on cars. I have not run into a single issue since.