I added several website links from a back up folder as they had been lost during the transfer from my old Mac to my new desktop. The back up folder is on the new computer on another drive. I opened up the links individually and then bookmarked them into my present bookmark list.
Everything worked fine.
When I was finished, the taskbar Sync icon said that I had new sites to sync so I allowed the sync but then I received the error message as listed in my header.