OK, it seems to be an OBJ size thing. The OBJ file I was using before had 256x128x2 (65536) faces. If I keep dropping the number vertices somewhere between 220x110x2 (48400 faces) and 230x115x2 (52900 faces) it stops working. The attached with 48400 faces works.
While I dislike (arbitrary) limits there may be good reasons. But should be documented (sorry if I missed it).
Is there any way to add parameters as input ports to the shader node?
Having fun writing shaders for realtime image mappings but having to hardwire constant parameters is "messy".
Yes I know about the method concatenating shader code and external text together outside the shader node, not so elegant either. :-)
What is the most reliable (accurate) method of determining the frame rate a composition is running at?
Related, is the Vuo window always locked to screen refresh or is there a way to create a window without vsync (old terminology, don't know what the right term is now).