Can you please check the images on the issue is happening does they have embedded GPS data on them.
The GPS field is blank. I don't believe there is any GPS data embedded.
Do you have any publish services set up? (SmugMug or other?)
I have JF Flickr, JF Photosafe, JF Zenfolio, and 500px publish services. At the time of the catalog move and test I also removed all publish folders, so they were effectively disabled at the time of testing and the problem still persisted. Could they still be a culprit or would that have eliminated them?
Still having issues.
I've found an inconvenient work around, which might provide info for a permanent solution. When I receive this error, if I delete all keywords from the photo it will then allow me to create a virtual copy. This has been tested many times.
Not a practical work-around to continue using.
Thanks for testing it and sharing the work around for the same, have you tried updating Lightroom to the latest update and check if that helps.