I think it may be related to installing V4.  I got the error too but only after installing V4.  It did not come up the first time I opened Poser because I had not added her runtime yet.  It came up the next time I ran poser AFTER adding her runtime to my list.  I just started Poser up again (because I foolishly clicked 'ok' the first time) and I didnt' get it again.  The pz3 I worked on after getting the error is fine and the one I saved prior to getting the error is fine as well.  Whew.  I better save this character as a .cr2 so I don't lose it.

I seem to recall getting an odd XML error way back when I first got V3 too.  But, I could be hallucinating that.  It was a long time ago grins