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Session restore option does not appear and can't restore from backup

  • 2 replies
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  • Last reply by cor-el

Robert Nickels
Robert Nickels
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This has happened twice now - I've had a main window open with 100+ tabs and a second window open with only one tab. All settings are as described to save history, etc. After closing Firefox and later restarting, only the window with a single tab is restored. I've saved the session backup files in another location and manual copied and renamed them into the main profile folder but in each attempt, only the single tab window was restored, which is obviously not what I want. I know the 100+ tabs are in the file because of the filesize and because I've used https://www.jeffersonscher.com/ffu/scrounger.html to scrounge the URLs from the backup file. But the point is that Firefox is NOT extracting the data from this file and restoring the other window, which makes me suspect there is a bug or problem with session restore when more than one window is open at the time of shutdown.

Thanks for any suggestions. Bob

This has happened twice now - I've had a main window open with 100+ tabs and a second window open with only one tab. All settings are as described to save history, etc. After closing Firefox and later restarting, only the window with a single tab is restored. I've saved the session backup files in another location and manual copied and renamed them into the main profile folder but in each attempt, only the single tab window was restored, which is obviously not what I want. I know the 100+ tabs are in the file because of the filesize and because I've used https://www.jeffersonscher.com/ffu/scrounger.html to scrounge the URLs from the backup file. But the point is that Firefox is NOT extracting the data from this file and restoring the other window, which makes me suspect there is a bug or problem with session restore when more than one window is open at the time of shutdown. Thanks for any suggestions. Bob

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Robert Nickels
Robert Nickels Question owner
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Thanks for the reply. What happened is, I'd somehow evidently unchecked the box to ask before closing multiple tabs and inadvertently clicked on the close window box. The 100+ tab window closed, but would not restore. After closing the other window with one tab, it would restore but not the first window. So it seems that the session restore function isn't working they way anyone would expect it to, since you'd want the entire session restored, not just one window. And when I examined the contents of the jsonlz4 file, all the 100+ tabs were in there, as "closed window" whereas the one that was restored was tagged as "open window".

cor-el
cor-el
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Use one of these to close Firefox if you are currently doing that by clicking the close X on the Firefox Title bar, especially if you have multiple windows open to prevent losing tabs in unnoticed windows.

  • "3-bar" menu button -> Exit (Power button)
  • Windows: File -> Exit
  • Mac: Firefox -> Quit Firefox
  • Linux: File -> Quit

You can check whether you have closed windows: History -> Recently Closed Tabs/Windows

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.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 with Firefox closed.

  • make sure to backup the current sessionstore.jsonlz4

You can try to restore a recent upgrade.jsonlz4-<build_id> when available or use a utility to browse Windows System Restore points to see if you can find a recent sessionstore.jsonlz4 file.

You can look at this tool to inspect a compressed jsonlz4 sessionstore file.