One thing I can think of is this is a Poser problem. I swear that Poser has a few bugs in it. The error message comes up quite a lot if you work on an image, prop, character, whatever, where the author/artists made a mistake. You load the item, and something can't be found. I think the missing geometry file is most often the culprit. Of course, I'm making a snap diagnosis without knowing more about what you're working on. And have you downloaded the Poser patch so you're up to 4.03?!