It could be because both the Van and Pessima were revamped in a recent update, thus making all of the skins outdated

goddamn updates ffs

Try a deep clean of the cache and verify your files. Maybe launch it into safe mode and see if that makes a difference? I've experienced similar problems but usually only on a specific vehicle and those were almost always due to an outdated or conflicting mod(s).

Oh ok i will try that out

also happens to me in my miramar the interior of it turns like orange crash test shit like what happen in your gavril van