ابحث في الدعم

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

FAILING TO RESTORE PREVIOUS SESSION AFTER PC POWER ACCIDENTALLY DISCONECTED AND SWITCHED OFF

more options

Today my PC switched off after an accidental power disconnection. Previously if such an event would happen, upon restart Firefox would ask if I want to restore previous session after "a crash" (also showing a sad bear icon) and i would restore my previous session successfully. Alternatively, I would manually press the "restore previous browsing session" button in the menu (if not prompted automatically to do so upon starting Firefox). However, today, after the disconnection, when I tried starting Firefox, it first ran some update before opening up and didn't give me the window asking if I want to restore previous browsing session. The button for restoring previous browsing session manually in the menu was also greyed out. Somehow the option/preference to restore previous session seems to have been unselected (but not by me!)... I have already tried working with some solutions I found through Google searches about this problem and posted on this forum (including working with previous.js - a file which I can not find) but I haven't been successful though I am not sure if I was getting everything stated right. In the sessionstore-backup folder I could only find recovery.js and recovery.bak files only, nothing else, despite folder settings being set to show hidden files. I must note though that my browsing history is still there, and again, having already opened my Firefox once, I have not closed it again so it's still running on the first instance (currently on the latest version of Firefox) after the crash/restart/update/failed-restore-of-previous-browsing-session...I hope that's hopeful :(

Please help, I had critical stuff I was working on through multiple tabs over the past "few months" and it would be a nightmare to try and comb through the history to restore it piece by piece considering that it shows even the stuff I had closed and was no longer working with...restoring the session would greatly help  :(

Today my PC switched off after an accidental power disconnection. Previously if such an event would happen, upon restart Firefox would ask if I want to restore previous session after "a crash" (also showing a sad bear icon) and i would restore my previous session successfully. Alternatively, I would manually press the "restore previous browsing session" button in the menu (if not prompted automatically to do so upon starting Firefox). However, today, after the disconnection, when I tried starting Firefox, it first ran some update before opening up and didn't give me the window asking if I want to restore previous browsing session. The button for restoring previous browsing session manually in the menu was also greyed out. Somehow the option/preference to restore previous session seems to have been unselected (but not by me!)... I have already tried working with some solutions I found through Google searches about this problem and posted on this forum (including working with previous.js - a file which I can not find) but I haven't been successful though I am not sure if I was getting everything stated right. In the sessionstore-backup folder I could only find recovery.js and recovery.bak files only, nothing else, despite folder settings being set to show hidden files. I must note though that my browsing history is still there, and again, having already opened my Firefox once, I have not closed it again so it's still running on the first instance (currently on the latest version of Firefox) after the crash/restart/update/failed-restore-of-previous-browsing-session...I hope that's hopeful :( Please help, I had critical stuff I was working on through multiple tabs over the past "few months" and it would be a nightmare to try and comb through the history to restore it piece by piece considering that it shows even the stuff I had closed and was no longer working with...restoring the session would greatly help :(

All Replies (6)

more options

Did Firefox create an upgrade.jsonlz4 file in the sessionstore-backups folder ?

Are you still using the same profile (i.e. no other data is lost) ?


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 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).

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.

more options

When the power goes out, the hard drive or parts of it can be corrupted.

  • Go to your local department/electronics store and look around for

a UPS (Uninterruptible Power Supply) that is useful for you. The lowest price is $50 +. There are also units on the market that plug into the computer. So if the battery gets low, it will shut down the computer to protect it.


  • Perform a System File Check to fix corrupted system files

Win 7, 8, 10, Vista: https://support.microsoft.com/en-us/kb/929833
Win XP: https://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/system_file_checker.mspx?mfr=true

Wiki - Windows 10 System File Check
http://answers.microsoft.com/en-us/windows/wiki/windows_10-update/system-file-check-sfc-scan-and-repair-system-files/bc609315-da1f-4775-812c-695b60477a93


  • If any program has a problem, download its full installer.
more options

cor-el said

Did Firefox create an upgrade.jsonlz4 file in the sessionstore-backups folder ? Are you still using the same profile (i.e. no other data is lost) ?

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 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).

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.

Thank you. To answer your first question...I don't know if it did but in the sessionstore-backups folder that file (upgrade.jsonlz4) is not there. To answer your second question, I would say yes - in the sense that I did not make any "changes" such as creating a profile on the browser and am pretty much using the default "profile" that was there all along right up to just before the power-off incident.

C:\Users\[pc-name]\AppData\Roaming\Mozilla\Firefox\Profiles\69fxzxq3.default-release-1590789727164\sessionstore-backups (That is the folder I'm referring to).

more options

It's possible for a power-off to corrupt various of Firefox's files, so this kind of data loss sometimes happens.

If you haven't already, please back up everything in sessionstore-backups to a place Firefox won't modify. Is there anything from around the right time to possibly have your missing tabs? You can use this tool on my website to preview the file contents -- load the file and then click Scrounge URLs:

https://www.jeffersonscher.com/ffu/scrounger.html

If you get some results that look good, use the Save List button to archive that list of clickable links as a web page. You can use this for recovery in case Firefox can't be persuaded to load that older session history file (through the trickery of renaming and swapping files).

Modified by jscher2000 - Support Volunteer

more options

jscher2000 said

It's possible for a power-off to corrupt various of Firefox's files, so this kind of data loss sometimes happens. If you haven't already, please back up everything in sessionstore-backups to a place Firefox won't modify. Is there anything from around the right time to possibly have your missing tabs? You can use this tool on my website to preview the file contents -- load the file and then click Scrounge URLs: https://www.jeffersonscher.com/ffu/scrounger.html If you get some results that look good, use the Save List button to archive that list of clickable links as a web page. You can use this for recovery in case Firefox can't be persuaded to load that older session history file (through the trickery of renaming and swapping files).

Let me try this action, but then again - about the bit of having "anything from around the right time to possibly have (the) missing tabs", I didn't quite understand that bit. Is it perhaps a file or something? Or a link to my browsing history (sinc e I can see some of the "pages" that had tabs during my previous session before the power-cut)?

more options

I meant any files that were last modified shortly before the cataclysm.