@poopman123 note that when you download a model on sketchfab, you should always have 2 folders in the downloaded archive:
source/: this folder will contain the model as uploaded by the user on sketchfab
textures/: this folder will contain the textures used in the sketchfab viewer. Those texture might have been added in the sketchfab editor and thus, not be available in the source archive.
So you'll often have to rebind the textures yourself if you want the model to look the same in sketchfab and in your software. Hopefully, one day there will be an universal exchange format (gltf) that will make this process easy but today this is still a cumbersome problem.
If your issue is that the archive you download does not contain the
textures folder then this is a bug and as Bart said, it would be great if you could point us to an URL with the problem.