I still have the materials in my VRay asset browser, but many of them appear to be trying to duplicate themselves (maybe as a result of the missing textures?). The next time you open Rhino, those textures are missing. It seems like when you apply a VRay material via the Rhino interface (applying a material to a layer, say) Rhino basically co-opts that material and places its textures in a Temp folder with random filenames. I am running Rhino 7 + Vray 5, most recent updates/drivers/etc. This is clearly a kludgy workaround but it is keeping me moving for the moment. i just 'remove' them and move on with my day. on re-open of the file, i still get a dialogue saying that I'm missing a few texture files. re-applying materials to objects/layers as needed unchecking 'can be overridden' for all materials in the vray interface deleting all materials FROM THE RHINO MATERIALS INTERFACE (not the vray one).

saving as a new file with 'save textures' unchecked I seem to have 'fixed' the issue below by: