You can open about:sync-log via the location bar to see if recent Sync logs are available. You can upload the file to a website like Pastesite if you can't post the content of the file in a reply.

• https://pastesite.org/

@cor-el

Thank you for responding. No logs are listed.

Hi

Given that Firefox Sync is not an online backup, but is designed to sync bookmarks and other data between devices - is your data in your other copy of Firefox on a different device?

@Paul

Yes, on a different device. I need to sync, as I have done before, between my home and work computers.

Just as a test, how about downloading a different version of Firefox (Beta, Dev, or Nightly) and verify that sync works. Download, unzip, and run firefox-bin from the folder and see if you have the same issue.

You can also send tabs to the other version as another test.

Thanks for your further suggestions. In the event the problem has been resolved by other means which are not entirely clear to me. It was my home computer that was not syncing. This morning I noticed that on my work computer I was not signed into Firefox, so I signed in. This afternoon my home version is syncing*. I am confused about this. I mean, my work version had been signed in recently, it had to be because it too was a new installation and needed its settings, bookmarks, etc. restored. I appreciate what Paul said about this not being an online backup, but I never have both of my computers online at the same time, so the information must be stored in a cloud, otherwise this home version would not have been able to retrieve it this afternoon. Does it get wiped after a certain time? Or what is it I am not understanding?

[* Not completely. Even though my sync settings say Firefox setting should be synced, some are not, e.g. "Homepage and new windows", "Show bookmarks toolbar".]