I rely on Firefox pretty heavily - multiple active windows with lots of browser panes open in each. The restart of active tabs when opening Firefox has been so reliable I've come to depend on it.

Try this if relying on a computer program :

• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer
• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Have you checked history to see if they are in there ?

• http://kb.mozillazine.org/Viewing_the_browsing_history_-_Firefox

• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data
• bookmarks and history: places.sqlite
• sessionstore.jsonlz4 for open tabs and pinned tabs (see also the sessionstore-backups folder)
• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

If a jsonlz4 backup can't be imported restored because it has the same structural problem as the database, a user can try to fix it using the Check/Repair JSON button on this page: https://www.jeffersonscher.com/res/scrounger_json.html

Please let us know if this solved your issue or if need further assistance.

Did Firefox create an upgrade.jsonlz4 file?

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.

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

@Pkshadow: History is still working, but it usefully shows webpages in the timeline that they were first opened up. What I don't have is a snapshot of all the browser tabs that were active at the time of the upgrade. (Any chance of adding this as an advanced feature somewhere ?!)

@Pkshadows & @cor-el: sessionstore.jsonlz4 looks like the way forward. I'll have a look shortly.

FWIW, here are the recent files inside the sessionstore-backups folder (there are also earlier files from July backwards, which I've not listed):

10 Aug 2018 01:31 upgrade.jsonlz4-20180807170231 10 Aug 2018 11:01 previous.jsonlz4 10 Aug 2018 15:54 recovery.baklz4 10 Aug 2018 15:54 recovery.jsonlz4

So it looks as if upgrade.jsonlz4-20180807170231 is going to be useful ?

Hi How do i use the session restore to get the 160 tabs back? I can see i have a some that were created today at the same time as firefox crashed, so will they have the old history or not?

Thanks

Copying sessionstore-backups\upgrade.jsonlz4-20180807170231 back into the profile folder did the trick.

Thanks for the help - much appreciated.

Cheers, Russell

Hi wub868

Did you make backup copiesof all files in the sessionstore-backups folder?

You can use this utility, already posted above, to check if a sessionstore file has the tabs you are looking for.

• https://www.jeffersonscher.com/res/scrounger_json.html