This may be the hard way (but the only way to do it on a MAC) but before you run it through UVMapper, load the .OBJ into a text editor (one that can handle large files) and search for the term "mtllib". Copy the whole line to your clipboard (i.e. "mtllib strtlite.mtl"). Then run the .OBJ through UVMapper then reload that and paste the mtllib line into the top of the file and save. btw - this problem seems to be coming from DAZ3D- if you look at the .OBJ in Poser's geometeries folder there is stuff there that should not be in an .OBJ. UVMapper strips out the bad stuff... sure would be nice if Poser did that!