We're calling on all EU-based Mozillians with iOS or iPadOS devices to help us monitor Apple’s new browser choice screens. Join the effort to hold Big Tech to account!

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.

Session Lost, Session Restore not working

David
David
more options

Windows restarted to update and all my 100s of tabs are lost (setting me back days of work!)... Firefox is set to always reopen previous tabs, but it didn't work. Recently closed tabs/windows are blank. The Restore Session page - about:sessionrestore - doesn't restore and lists no previous windows/tabs. I went into my sessionstore-backups folder and grabbed a previous.jsonlz4 that has some data but am not sure what to do with it.

Please help! This is a devastating loss of information, as I use my tabs as a to-do list and had many in-progress projects with resources that I cannot all recover just through history.

Windows restarted to update and all my 100s of tabs are lost (setting me back days of work!)... Firefox is set to always reopen previous tabs, but it didn't work. Recently closed tabs/windows are blank. The Restore Session page - about:sessionrestore - doesn't restore and lists no previous windows/tabs. I went into my sessionstore-backups folder and grabbed a previous.jsonlz4 that has some data but am not sure what to do with it. Please help! This is a devastating loss of information, as I use my tabs as a to-do list and had many in-progress projects with resources that I cannot all recover just through history.

All Replies (4)

David
David Question owner
more options

I tried to use that copied previous.jsonlz4 file but got this error in sessionstore-logs:

1718308459556 SessionStore ERROR The session file is invalid: : TypeError: state.windows[0] is undefined(resource:///modules/sessionstore/SessionStore.sys.mjs:1163:11) JS Stack trace: initSession@SessionStore.sys.mjs:1163:11 onBeforeBrowserWindowShown/<@SessionStore.sys.mjs:2035:35

jscher2000 - Support Volunteer
jscher2000 - Support Volunteer
  • Top 10 Contributor
more options

Hi David, when you say you tried to use it, how did you try to use it? Could you take a look at this reply:

https://support.mozilla.org/en-US/questions/1449541?page=2#answer-1657106

David
David Question owner
more options

Aha! Yes, jscher2000, that did the trick! I was missing the last step: hiding the old sessionstore.jsonlz4.

I will also download Tab Session Manager just in case there's an issue again. I'd had this happen a year and a half ago on a different computer with a different Firefox account.

Thanks so much! Your instructions were so much clearer than I've been able to find before, and your speedy reply was a lifesaver. You have restored my faith in Firefox!

jscher2000 - Support Volunteer
jscher2000 - Support Volunteer
  • Top 10 Contributor
more options

Hi David, thank you for reporting back.