I have Poser 5 it was working perfectly fine then all off the sudden every time i render all the charaters become completelt black. I opened the same file in P4 and its perfect what the problem.

Had similar, in my case it had something to do with the lights,had some "black lights" in poser and after deleting them everything rendered as before.

Attached Link: http://www.renderosity.com/messages.ez?Form.ShowMessage=910494

I had this on one of my recent renders in P4, it was because the camera was "inside" the ground plane. this may also happen I guess if its is on a wall or prop. move your camera a bit and try to re-render. or, try it from a different camera. if these don't work....see the "lights" solution above. Evo

With all the new light sets around I've been running into this more and more. I've never quite figured the exact details out, but if a light changes type when switching sets, it goes black. If you have pro pack or Poser 5 it's easy enough to fix with a python script that deletes all the lights. There are a couple available (have to hunt, I don't have links). Only other solution is close and reopen Poser.