Hello,

Thanks for your question here!

We have seen this odd behavior a couple times before, but it seems that it can be fixed in a few different ways, please see below:

First, you can try to restart your computer. It should make the problem dissapear.

Another option is to reinstall the software from here: OpticStudio Downloads · MyZemax

If these don’t solve the issue, there could be something odd with the temp files in the DATA folder, so you can try clearing the windows temp files with a disk cleanup, or you can rename the ZEMAX folder in documents, which will force it to copy a new fresh set of sample files when OpticStudio is reopened.

Finally, you can toggle between normal view and express view, as this problem has not been reported when using express view:

I hope this helps!

Best,

Csilla