Okay it seems I may of jumped the gun a little here, I did a bit more research for you on the issue.

The developer of the product addressed this issue on the Daz Forums a while back. It appears that the file it calls for is part of another product "victoria-4-for-genesis-2-female" basically its a custom UV for for Genesis 2 Female that matches V4 to allow using V4 material Presets.

The developer says that you should be safe to just ignore the error message, as it bears no relevance to the actual conversion:

"Are you still able to do the pose conversion? If yes then just ignore that message because it has no relavance to the pose converting process." - ZevO