This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Avatar for Username

Search Support

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

This thread was archived. Please ask a new question if you need help.

How to recover session using "upgrade.js" ?

MoustacheMike
MoustacheMike
more options

My computer auto-restarted overnight while I slept, come morning time my wife was checking her emails online... which caused my previous session to be lost. I have some important tabs that I need to recover, and thankfully I was able to find my session in one of the "upgrade.js" files.

I copied the "upgrade.js" file and renamed it to "sessionstore.js" as mentioned elsewhere on this support forum. It has not worked, not sure if my version of Firefox is incompatible with that advice... or... if there are details missing with regards to all the steps I have to take to restore the session.

Please advise, I need to recover my tabs ASAP

My computer auto-restarted overnight while I slept, come morning time my wife was checking her emails online... which caused my previous session to be lost. I have some important tabs that I need to recover, and thankfully I was able to find my session in one of the "upgrade.js" files. I copied the "upgrade.js" file and renamed it to "sessionstore.js" as mentioned elsewhere on this support forum. It has not worked, not sure if my version of Firefox is incompatible with that advice... or... if there are details missing with regards to all the steps I have to take to restore the session. Please advise, I need to recover my tabs ASAP

Chosen solution

I failed to pay attention to detail earlier...

Instead of putting the renamed file into the main profile folder I kept trying to get it to work by placing it in the "sessionstore-backup" folder.

Problem is solved, thanks

Read this answer in context 👍 0

All Replies (2)

cor-el
cor-el
  • Moderator
  • Top 10 Contributor
more options

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

You can backup the session files in the sessionstore-backups folder in the Firefox Profile Folder to make sure not to lose possible important session data. You can find these files in the sessionstore-backups folder: 

previous.js (cleanBackup: copy of sessionstore.js from previous session that was loaded successfully)
recovery.js (latest version of the sessionstore written during runtime)
recovery.bak (previous version of the sessionstore written during runtime)
upgrade.js-<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.js to replace the current file (make a backup copy of the current sessionstore.js).

See also: http://www.ghacks.net/2014/06/27/mozilla-launches-improved-session-restore-firefox-33/

You can use this button to go to the current Firefox profile folder:

MoustacheMike
MoustacheMike Question owner
more options

Chosen Solution

I failed to pay attention to detail earlier...

Instead of putting the renamed file into the main profile folder I kept trying to get it to work by placing it in the "sessionstore-backup" folder.

Problem is solved, thanks