anyone? no help?

If you use the Time Machine or other backup then try to restore file(s) from this backup.

• http://www.apple.com/support/timemachine/

For the tabs you need the sessionstore.js file.

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.

• Help -> Troubleshooting Information -> Profile Directory: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

Firefox uses sessionstore.js in the profile folder to store session data. Sessionstore.js 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.

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:

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

Sorry, it did help but I am not sure of all the process I have to go through. On the computer HD, I have found where the sessionstore- back up is located and all the files have today's date so these would load the recent setup, the pages I have opened after I lost my tabs. correct? On my External HD there are 3 upgrades and are dated Jul Aug and Sept 2016, way in the past even though I do the back up weekly... why is not clear. In the CCC External drive back up archives/ March 04 2017 / users/my user name/library/application support/firefox/profiles/ y8mn95ie.default-1423602233278 there are 3 files dated Feb 2017 which I should use to substitute the ones above, correct?

not clear on this passage "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." I have shut down computer since I posted my request for help so Firefox would have update the back up to the new tabs I have used, correct?

If I have used Firefox and made other tabs will it not upload the present configuration if I use the folder on the computer? .... please clarify :-)

I forget, all this happened after upgrading Firefox. I have an old version of Apple OS and last time I tried upgrading Firefox it did not a version for it. But this time it did but it changed my settings to open old session and asked me to choose each time with the button Open previous session. I thought it was just how the new version worked but one day I clicked on a link before I had opened the old session and all went! ...

mmm I tried substituting the old files but it gives me the current set up not the one I lost...

To restore tabs from a specific sessionstore file in a backup, either sessionstore.js or an upgrade file in the sessionstore-backups folder, you need to copy this file the the current profile folder and rename the file to sessionstore.js with the Firefox application closed (Firefox > Quit). You may have to look in "History -> Recently Closed Tabs/Windows" if you aren't using the "Show my windows and tabs from last time" setting.