I can't seem to track this one down and it seems like it should be really straight forward. I have a mating surface that is elliptical. The parts are dimensioned the same to five places (in mm) yet the top surface of the two parts is not the same. There is a bit of proprietary geometry not shown so I cannot post the parts as is. Perhaps if this drags out I can start deleting features.
This is what it should be. Part number 1:
This is the mating part and the dim that is creating the issue. Part 2:
Here's the issue it creates. The ray trace software expects the surfaces to be defined as far as the internal and external materials. It expects to "see" two mating surfaces in this case but does not and so show error points as an "x".
This gets to be exhausting after a short while....