My bookmarks disappeared from my Firefox Sync.
The only ones left are the mobile bookmarks. All my desktop bookmarks I had categorized into folders are gone.
Additional System Details
- Intel web components updater - Installs and updates the Intel web components
- Intel web components for Intel® Identity Protection Technology
- Shockwave Flash 24.0 r0
- User Agent: Mozilla/5.0 (Windows NT 6.3; rv:51.0) Gecko/20100101 Firefox/51.0
Try to restore a JSON backup.
- Bookmarks -> Show All Bookmarks -> Import & Backup
The name of a JSON bookmarks backup file includes a total item count (folders and separators included) and an hash value to prevent saving the same backup more than once.
- bookmarks-YYYY-MM-DD_<item count>_<hash>.jsonlz4.
You may have to restore an older JSON backup manually if recent JSON backups are already affected.
If you use Sync then best is to disconnect Sync while performing maintenance/repair efforts to files in the Firefox profile folder.