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firefox does not restore previous sessions anymore

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  • 31 have this problem
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  • آخر ردّ كتبه jscher2000

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i turned on Firefox today and found out that it's showing a new session instead of my previous session. which happened right after the update. then after i finished using my PC for the day i chose the option to restore previous sessions instead of showing homepage(i don't have one) then i closed and re-opened Firefox. still showed me a new session.

and i also need to mention got one of those hijacker junkwares which seems like i caught before or after the update (i followed online instructions to remove it) but removing it did not solve this problem.


i'm not sure which one is the reason for the problem. so i would be grateful for any kind of help :)

الحل المُختار

Could you double-check that Firefox is actually recording the change you make on the Options page. Here's how:

Part 1: The about:config page

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.

(2) In the search box above the list, type or paste start and pause while the list is filtered

(3) Double-check that the browser.startup.page preference is bolded and "user set" to 3 (the value for restoring your previous session windows and tabs). If this preference does NOT show 3 after you make your selection on the Options page, try double-clicking it and setting it to 3 manually. Will it take?

If the preference status is "locked" then we'll need to assist you investigating the source of the lock.

Part 2: The prefs.js file

If about:config is correct, then Firefox also should have recorded that value in the prefs.js file. There may be a few minutes' delay in updating that file on disk. Here's how you can check it:

Open your current Firefox settings (AKA Firefox profile) folder using either

  • "3-bar" menu button > "?" button > Troubleshooting Information
  • (menu bar) Help > Troubleshooting Information
  • type or paste about:support in the address bar and press Enter

In the first table on the page, click the "Show Folder" button. This should launch a new window listing various files and folders in Windows Explorer.

Scroll down to prefs.js, right-click it, and choose Edit. (Do not double-click a .js file, since then Windows will try to execute it in the Windows script interpreter with unpredictable results.)

The file usually will open in Notepad, and it's generally alphabetical, so you can scroll down and look for a line which reads:

user_pref("browser.startup.page", 3);

Is it there?


We have a general support article on possible reasons that a preference change which you make during a session might not actually get saved to disk, or might be ignored or reverted: How to fix preferences that won't save.

We also have noticed that some utility software such as Advanced SystemCare will roll back settings changes between sessions. If you have that or any other software with a home page protection, browser settings protection, or similar feature, try disabling that feature.

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All Replies (4)

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Hi Irish181, AppData is indeed a hidden folder.

sessionstore.js does not exist while Firefox is running, so that's normal. (recovery.js does not exist when Firefox has been shut down normally. Only one normally exists at a time.)

It's strange not to have a previous.js file. I'm not sure what accounts for that.

Did you recently used the Refresh feature? Please check your desktop for a folder named Old Firefox Data and if you find one, drill down into there for older files from the sessionstore-backups folder(s) in there.

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Hello jscher2000,

Thank you for your help. This is not the first time I have had a FF crash and found all previous sessions wiped out!

Is the correct syntax for the folder name "Old Firefox Data" or, "Oldfirefoxdata"?

I've searched the C:\ drive for each but, I've found neither.

Would the Old Firefox Data folder have any files with any file extensions unique enough for me to search for "*.ext" and get into the "Old Firefox Data" folder that way?

I've installed the mozdev.org "Session Manager" so, I hope I'm covered for any future FF crashes. But, it would be nice to restore the last lost session. I had a lot of tabs open and will likely not be able to get back to many of them.

Let me know if you have any thoughts or, if the FF crash and restart may have erased those tabs forever! 10Q

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The "Old Firefox Data" folder should be on the desktop if this folder had been created by doing a refresh. If you do not see it there then you probably won't find it elsewhere apart from the recycle bin if you have deleted this folder.

Do you have a sessionstore.js file in the Firefox profile folder?

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

  • Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)

Firefox uses the sessionstore.js file in the profile folder to store session data, but this file 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.

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:

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Hi Irish181, if you are doing a global search for, say, previous.js, then you may want to adjust two windows settings:

  1. 1
  2. 2