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.

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

How do I open closed windows from sync?

  • 2 replies
  • 1 has this problem
  • 6 views
  • Last reply by cor-el

more options

I took laptop away from wifi, box came up, chose stop plugin. came back, opened Mozilla, there was no option to restore previous session. I had 4 windows and numerous tabs open; now lost. History is a minefield. I have Sync, but don't know how it works?! - Would sync restore my windows. I would like to contact Moz, as I am a donor to them.

I took laptop away from wifi, box came up, chose stop plugin. came back, opened Mozilla, there was no option to restore previous session. I had 4 windows and numerous tabs open; now lost. History is a minefield. I have Sync, but don't know how it works?! - Would sync restore my windows. I would like to contact Moz, as I am a donor to them.

All Replies (2)

more options

This is Mozilla Firefox support.

Sorry, Sync isn't going to be of any use on that device if Restore Session was greyed out on that device.

You could check another device that is connected to that same Sync account and see if that session appears on that other device. If you would load that 'missing' session on the 2nd device and then close it, it should appear back on the 1st device as a session from another device.

Hope that makes sense to you.

more options

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.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:

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