Sorry for your loss of data. Sync wasn't intended a a backup medium (it is intended to synchronize Firefox data between multiple device or Profiles) and the Sync server doesn't keep backups of user data (the "original" data should still be on at least one device connected to that Sync account in the case of failure or loss of one particular device).

Have you disconnected from the Sync server and attempted to restore a backup from within the new Firefox installation? That might get back what you lost as a result of running the 2nd "sync" at least. From my own observations while using Sync, Firefox usually creates or updates the backup file quickly after a "sync process". It does only retains one "backup" for each "day", but it doesn't wait to make the daily backup at a specific time - it seems to be an ongoing process.

Apart from, I provide you some articles. I hope you can take help from those too. https://support.mozilla.org/en-US/kb/ive-lost-my-firefox-sync-account-information https://support.mozilla.org/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file You can try to restore the bookmarks from a recent JSON backup in the bookmarkbackups folder.

http://kb.mozillazine.org/Backing_up_and_restoring_bookmarks_-_Firefox

Can you access the Sync account here?

• https://accounts.firefox.com/settings

cor-el said

Can you access the Sync account here?

• https://accounts.firefox.com/settings

I can log in there but all it lets you do is delete your account or log out. There is still no data when I push sync now.

Could you post a Sync log to see if there is a problem?

You can check the about:sync-log page via the location/address bar to see if there are error logs available. You can upload a recent log to this website if the log is too big to put in a reply.

• http://pastebin.mozilla.org