Several staff have reported to RCA that they are unable to ‘create a copy online’ of the NLCT templates within SharePoint/OneDrive.

This is not local to Rice and is a known issue for Microsoft, which is investigating the problem

https://learn.microsoft.com/en-us/answers/questions/5665155/unable-to-save-a-copy-any-more

As a workaround while waiting for a fix, try downloading a copy of the file from the web application and either working with the copy on your local machine or manually uploading the downloaded copy back to OneDrive to work with it there.