I’m having some trouble running a tolerancing script in OpticStudio, where I continually get the “nominal criterion cannot be computed” error when I attempt to run the script. I’ve tracked it down to a CPAR compensator I’ve defined on a Zernike Fringe Phase surface. I’m attempting to use the phase surface Z9 term to null the system spherical for each Monte Carlo file in the tolerance analysis.

I’ve confirmed the compensator is defined correctly (CPAR Surf# Param23), and I’m able to set the same parameter to a variable and optimize in the nominal design file, so I can’t understand why the tolerance script cannot implement this as a compensator. If I comment out the CPAR line, the nominal criteria evaluates and the script runs without issue. Can anyone explain why I’m unable to use this compensator?