This has not been tested or supported, since the plug-ins are not designed to work with Poser 5. That said, if you want to try it: 1) Be sure you have no Poser 5 features in your scene (shaders,hair, cloth, etc.). 2) Try opening the scene in P4. If it works, go ahead and try hosting it. Sorry if it sounds redundant, just make sure you have no P5 features in use. Alternatively, you can try using P5 figures in P4.