Hi! Late reply but I thought it might help other users.

This error can happen when the data is corrupted or used by another application and OpticStudio cannot access it until it’s released. Typically, the Openclipboard Failed error may be a result of Windows system file malfunction.  There can be lots of events that can have resulted in file errors: a partial install, an incomplete file erasure, improper deletion of programs or components.  It may also be caused if the clipboard is caught by another application, virus or adware.

The easiest I think is to type clipboard in your window search and then select clear clipboard.

Here is a set of instructions that one of my colleague wrote and you can try if the above doesn’t work:

• first go through the steps listed in Troubleshooting Your OpticStudio Installation to make sure the program and all of the prerequisite software is properly installed, and no conflicting third-party programs are installed: https://support.zemax.com/hc/en-us/articles/1500005487861-Troubleshooting-your-OpticStudio-installation
• We found there is a .NET Framework bug about OpenClipboard Failed, which is fixed in version of 4.5.  You can also find more information about how to update .NET Framework in the Troubleshooting article above.
• If after updating to .NET Framework to 4.6 or higher, please contact the support.