I just tried to report the same bug a few minutes ago, but unfortunately, we switched to ANSYS subscription model so the zemax users are not recognized and they might have ignored my report.

They have changed the CAD library to a new one and have obviously not tested that the new one could open STEP or IGES files 

The fix is fortunately simple, uncheck the “Parasolid libraries” option and it will work again

The working library seems to be the “legacy” zemax one, not the more recent “ACIS” one.

There was a library change ~1-2 years ago to use ACIS core (with a similar option to use it). This would use SAB and ZAN files to store the shape and the face/surface definition. The previous library, the “legacy” Zemax CAD library used ZOF and ZEN files instead. ZAN and ZEN are very important if you set different properties to different surfaces in the CAD object. Both libraries do not always number the faces the same way, so the properties may be applied to different surfaces when switching the option on/off.

It appears that unchecking the parasolid option will use the “legacy” libraries, as Zemax creates ZEN and ZOF files. I would advise that anyone applying coating should doublecheck that their face/surfaces are still correct.

This applies to anytime the libraries are changed, or an old model is opened with a new library.

Thank you!

Unchecking the parasolid option solved my problem.

Shoutout to whoever’s doing testing these days...

Hi Heikko,

I am in discussion with Zemax support, I have found that it seems related to the OS decimal separator. Do you happen to live in a country using the comma ? If so, could you try if setting the decimal separator to the dot allows the parasolid library to work ? This is in the “Region” settings (accessible by the “old” control panel in Windows 10 or 11. In the “Additional settings...” window:

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Hopefully this works for you. That would explain why it did not get detected.

Hi Ray,

yes, I’m living in a comma country. Changing the global setting would affect other programs too, I would prefer a different solution.

Kind regards,

Heiko

Hi Heikko,

I understand that for long term it is not an ideal solution, but could you check if it the parasolid library works with dot as decimal separator just to confirm the workaround. That could be useful information for the developers to track the bug.

Also, ray tracing with the old library is ~10 times slower than with the ACIS or parasolid libraries (and the ACIS libraries is not available in 2023 R2).

Excel can be told to either follow the OS or use a dot/comma given separator (if Excel is one you want to keep using the comma).

Hi Ray,

after changing from Comma to Dot, I was able to load a few files with STP parts. For the other parts I get Error 72: Unknown error. I guess the new library is limited in the support of STEP file format. In my case the origin of the STEP files is CATIA V5.

Hi,

I have the same situation here in the UK (no comma) with OpticStudio 23.2.1. Again getting Error 72: Unknown error with STEP files generated by CATIA V5.

Using the parasolid libraries solved for me the problem in Comma-Country Germany.

Hallo Heiko,

Did you mean to say “disabling” the parasolid libraries as you wrote 4 months ago ?

My mistake,

yes disabling helps.