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Lost all my tabs after FF update

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Shortly after last FF update (59.0.2), all my tabs went missing -- a hundred or more. There was no option to restore them (options under 'History' were all grayed out), and couldn't find any 'session'-type file in my profile to go back to (it was like they All got updated--even the backup/restore/previous session files). Tried running Recova to see if any deleted or corrupted session-related files to restore from, but no luck.

Finally gave up and started with new tabs, but every few times I close and later re-launch FF, it again loses whatever tabs I had, with no way to restore them.. and I can't determine any related cause/effect. Seems random.

Never had this issue with missing or disappearing FF tabs and have been using FF reliably for a decade. Running Windows 10 (rebooted several times) and no issues with other programs; have run several malware programs just in case, but all clean. No recent add-ons or extensions or related updates. My FF has bare/minimal add-ons.

Thanks for any help. Love FF, but need tabs to work properly.

Shortly after last FF update (59.0.2), all my tabs went missing -- a hundred or more. There was no option to restore them (options under 'History' were all grayed out), and couldn't find any 'session'-type file in my profile to go back to (it was like they All got updated--even the backup/restore/previous session files). Tried running Recova to see if any deleted or corrupted session-related files to restore from, but no luck. Finally gave up and started with new tabs, but every few times I close and later re-launch FF, it again loses whatever tabs I had, with no way to restore them.. and I can't determine any related cause/effect. Seems random. Never had this issue with missing or disappearing FF tabs and have been using FF reliably for a decade. Running Windows 10 (rebooted several times) and no issues with other programs; have run several malware programs just in case, but all clean. No recent add-ons or extensions or related updates. My FF has bare/minimal add-ons. Thanks for any help. Love FF, but need tabs to work properly.

All Replies (5)

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Hi, sorry to hear that. There was no OldFirefoxProfile Folder on your Desktop ? If was possible to recover.

I would think something got corrupted during the update. You can try : uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files , C:\Program Files(x86) & C:\ProgramData Then restart system. Then run Windows Disk Cleanup. (Note: This should be Pinned and run Weekly, If never done below expect 10's of gig's) Then run it again and click the button that says Cleanup System Files. Note: your Firefox Profile is saved. But you should make a back up before you do :

Reinstall with Current Release Firefox 59.0.2 with a Full Version Installer

You can also try a Extension by Copy/Paste (will see why) Session Manager to the Search bar in this URL : https://addons.mozilla.org/en-US/firefox/extensions/ Please let us know if this solved your issue or if need further assistance.

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Hi, thanks very much for your helpful reply, Pkshadow.

Will try your suggestions in a couple days when I have time to implement--want to make certain I've got proper backups!

Btw, extra info for anyone else.. I'm running the 64-bit ver of FF.

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Firefox uses the sessionstore.jsonlz4 file in the profile folder to store session data. The sessionstore.jsonlz4 file is only present when Firefox is closed. The sessionstore.jsonlz4 file is created from recovery.jsonlz4 when you close Firefox and is removed and copied to previous.jsonlz4 when you start Firefox to make is possible to restore the session at any time.

Backup the session files in the sessionstore-backups folder in the Firefox Profile Folder to make sure not to lose possible important session data. Do NOT close Firefox when Firefox is already running.

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

You will normally find these files in the sessionstore-backups folder:

  • previous.jsonlz4 (cleanBackup: copy of sessionstore.jsonlz4 from previous session that was loaded successfully)
  • recovery.jsonlz4 (latest version of sessionstore.jsonlz4 written during runtime)
  • recovery.baklz4 (previous version of sessionstore.jsonlz4 written during runtime)
  • upgrade.jsonlz4-<build_id> (backup created during an upgrade of Firefox)

You can copy a file from the sessionstore-backups folder to the main profile and rename the file to sessionstore.jsonlz4 to replace the current file (make sure to backup the current sessionstore.jsonlz4).

Firefox 56+ releases compress the files in the sessionstore-backups folder and sessionstore.jsonlz4 with LZ4 (.jsonlz4 instead of .js), so it is no longer easy to inspect them.

See also:

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Pkshadow said

Hi, sorry to hear that. There was no OldFirefoxProfile Folder on your Desktop ? If was possible to recover.

Sorry, meant to respond to your question re an OldFFProfile/Folder on my desktop -- No, never saw any such folder, thanks.

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cor-el said

Firefox uses the sessionstore.jsonlz4 file in the profile folder to store session data. The sessionstore.jsonlz4 file is only present when Firefox is closed. The sessionstore.jsonlz4 file is created from recovery.jsonlz4 when you close Firefox and is removed and copied to previous.jsonlz4 when you start Firefox to make is possible to restore the session at any time. Backup the session files in the sessionstore-backups folder in the Firefox Profile Folder to make sure not to lose possible important session data. Do NOT close Firefox when Firefox is already running. ..

Thanks, Cor-el, for the additional info re session files and how they function -- that helps clarify some confusion I had.

Will start backing up the session folder periodically. Wondering if my problem, at least initially, stemmed from this file getting corrupt or mishandled somehow:

" upgrade.jsonlz4-<build_id> (backup created during an upgrade of Firefox)  " ?

Not sure why, but haven't lost my tabs the past couple days, even having closed/relaunched at least half a dozen times.

Thanks for the helpful responses here! Still plan to do a full backup and re-install FF -- it's likely well past time irrespective of the lost-tabs issue.