OBZ is the Poser compressed form of the OBJ file format.

You show the Poser 6 James folder however JamesG2 is not listed. I wanted to be absolutly certain which version you were using but sadly at this point I still can not be. I do know that if the wrong one is used you will get the error that you are observing.

Is the suite a legitamate freebie that I could legally download and convert for myself? At this point I think that is the only way I can show you, step by step how to proceed.