I have found that this happens a lot when the uv map has been corrupted or doesn't have one. Download the free uv maper and carry the props obj into it and asign a map then save it after which you can import it back into poser and you should have no problem seeing the prop. Hope this helps
It is this uv map's template that you use to add texture to your prop by carrying it into a graphs program and adding material to it. Hopes this helps.