Thank you all. Batch rendering is working great. It took a little exploration before I realized that what is rendered is the saved file and not the display in the assembly room. I had tried copying objects to a new file earlier as Ed suggests, but it only worked once. Then it, too, was corrupted. I do have a complex layers list shader with twelve shader domains on the principal object. Could this be the source of the problem? It is thrilling, Ed, after you get a working strategy and the lump in your throat and the knot in your belly go away. Again, thank you and thanks to the Carrara community from whom I have learned so much over the last three years. Paul