"A "preview" material is automatically added by Poser even if you remove it in Blender.

The object file coming out of Blender does NOT have a preview material.

When cleaning the cr2 (changing the 2 paths to your new object file name and location) you also remove ALL materials from the cr2. ALL."

Just an experiment: take a poser figure cr2... delete all materials within that file, including preview. Now, take the referenced obj file and delete all material definitions within that file. Open poser, load that figure. What do you see?