Thanks Bob. Oh dear, I made a real mess of this. I just knew I was going to have problems packaging this. Bad housekeeping, I've got diffrent versions of files with diffrent names scattered all over the place.

I've added the "blank.obj" (essentially just an empty file), and changed the geometry refference in the cr2 to "Rings_LB.obj", and uploaded the new zip. Hopefully it is OK now.