One thing that I found ALWAYS causes the C mode exception, is if you add a P3 morph that has invalid geometry coordinates to a P4 head. It will make the cr2 crash every time without fail. I have no idea what causes the render crash, I always seem to run into that one when I am rendering a 600 frame animation, and Poser crashes on the 450th frame or something like that. Co(V)(V)union