Hello Axion,

Thanks for your question here!

May I ask which version of OpticStudio are you using? We’ve had a few other users report similar error message formerly in older version of OpticStudio, but often it’s just a weird temporary problem Windows had. This has been resolved by either relaunching the help files, restarting OpticStudio, or launching the Help files directly from 'C:\Program Files\Zemax OpticStudio\Help' folder. Can you open the Help directly from this route?

If the problem persists, please let us know so we can investigate further!

Best,

Csilla

Hi Csilla,

Thanks for quick answer. The problem was resolved: it was locked access to MS HTML Help Executable .

Apparently,  now there is a new trend, where IT departments are  implementing new policy restricting administrative privelages for users on local machines. After they unlocked MS HTML Help Executable the Help menu started working again.

BR,

Axion