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Why has firefox recently been restoring a previous version of my tabs on startup, but not any changes I have made to those tabs during the last browsing session

  • 3 replies
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  • Last reply by cor-el

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Hi. Windows 7 computer, i have hundreds of tabs in 7 windows. Firefox faithfully restores those (any occassional problem i have had i resolve by using system restore) but lately it has been reverting to what appears to be a certain saved status of tabs and not saving any changes i have made during the most recent browsing session. Sporadically, though, it will save those changes, but at this point that's about once every two weeks or so and i am fully shutting down my computer at least 2-4 times a week and thus restarting my browsing session. Normally i shut down while firefox is running, then when i start firefox back up next time it gives me the option to restore session, which i do. Maintaining all these tabs is the easiest way for me to save information, but i would like for it to properly save changes after each session. Any ideas? What i DON'T want to do in order to try to fix this problem is to lose the tabs/windows that ARE currently saved. Thanks all.

Hi. Windows 7 computer, i have hundreds of tabs in 7 windows. Firefox faithfully restores those (any occassional problem i have had i resolve by using system restore) but lately it has been reverting to what appears to be a certain saved status of tabs and not saving any changes i have made during the most recent browsing session. Sporadically, though, it will save those changes, but at this point that's about once every two weeks or so and i am fully shutting down my computer at least 2-4 times a week and thus restarting my browsing session. Normally i shut down while firefox is running, then when i start firefox back up next time it gives me the option to restore session, which i do. Maintaining all these tabs is the easiest way for me to save information, but i would like for it to properly save changes after each session. Any ideas? What i DON'T want to do in order to try to fix this problem is to lose the tabs/windows that ARE currently saved. Thanks all.

All Replies (3)

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You can check for problems with the sessionstore.js file in the Firefox profile folder that stores session data. Deleting sessionstore.js will cause App Tabs and Tab Groups and open and closed (undo) tabs to get lost and you will have to recreate them (make a note or bookmark them if possible).

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


Note that your System Details List shows multiple Flash plugins.

  1. Shockwave Flash 18.0 r0
  2. Shockwave Flash 11.9 r900

You can find the installation path of all plugins on the about:plugins page.

You can check the Flash player installation folder for multiple Flash player plugins and remove older version(s) of the plugin (NPSWF32) and possibly (re)install the latest Flash player.

  • (32 bit Windows) C:\Windows\System32\Macromed\Flash\
  • (64 bit Windows) C:\Windows\SysWOW64\Macromed\Flash\

All versions of the Flash plugin have been disabled (blocklisted) by Mozilla because of disclosed security vulnerabilities in the plugin that Adobe needs to address via a security update.


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Thanks for mentioning the fact that i have 2 versions of flash. However, since they are currently disabled this wouldn't be causing my problem, correct? Also thanks for the suggestion to basically wipe out my session info and start over. While this might solve the problem, my goal was to solve the problem WITHOUT resorting to such drastic measures. ("Making note of" over 1000 web pages is a hassle which i am willing to go thru only as a last resort.) Thanks for the attention tho.

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This still looks like an issue that the sessionstore.js file isn't updated and you have an older version in the profile folder that restores the tabs.

The sessionstore.js file is normally created from recovery.js when you close Firefox and is removed and copied to previous.js when you start Firefox.

You can backup the session files in the sessionstore-backups folder in the Firefox Profile Folder to make sure not to lose possible important session data.

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).