I think the textures of the meshes you see that are yellow and black are missing, try to find their textures and make them be in the same place as the mesh archive, if not, the mesh texture won't work, thats what i would do, if that's not the problem i think you should ask your friend where did he got the meshes and ask the owner of the meshes if they know how to fix the problem, hope this helps..
-Huggles-