No pages explain what sync really is. I would assume the data stored on firefox central for my account would be compared to the data (bookmarks in particualr) on the device and that the 2 lists are shared equally so both end up different from the start but the same as each other. Now I dont know and help pages do not discuss what sync actually does!
So my laptop went crazy today and the bookmarks listed suddenyl all point to totally different webpages, some of which I had visited recently but not bookmarked. It follows I have lost my bookmarks then. So I used sync, thinking it would restore my bookmarks correctly but it did not - it seems to have uploaded the new false bookmarks to Firefox, which in turn downloaded them to my other devices so, thanks to Firefox sync, I have effectively lost dozens of bookmarks across all my devices and I cannot find help which is useful.
Is there a way to restore those devices to the bookmarks stored yesterday?
If you use Sync, best is to disconnect Sync temporarily during troubleshooting.
This could be a problem with the places.sqlite and favicons.sqlite files in the Firefox profile folder.
- use the "Places Database" -> "Verify Integrity" button on the "Help -> More Troubleshooting Information" (about:support) page
If errors are reported with "Verify Integrity", close and restart Firefox or reboot and retry.
If "Verify Integrity" cannot repair places.sqlite, rename/remove all places.sqlite and favicons.sqlite files in the Firefox profile folder with Firefox closed. Firefox will rebuild places.sqlite and restore the bookmarks from the most recent JSON backup in the bookmarkbackups folder.
- keep a backup copy of places.sqlite in case a new places.sqlite database has to be created
- you lose the history when a new places.sqlite is created
You may have to restore an older bookmarks backup in the bookmarkbackups folder via the Bookmarks Manager (Library).
- Bookmarks -> Manage Bookmarks -> Import & Backup -> Restore
You can use the button on the "Help -> More Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page (Root directory).
- Help -> More Troubleshooting Information -> Profile Folder/Directory:
Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder
Best is to reconnect one device at the time and wait for the initial Sync to finish before connecting another device once you have fixed the bookmarks.