While Firefox is open, it maintains a file named recovery.js in the sessionstore-backups folder, which is a folder inside your profile folder. If you are planning to restore a previous session, start by backing up recovery.js and previous.js to a safe location that Firefox won't overwrite, such as your Documents folder.

When Firefox is closed (without crashing), it creates a sessionstore.js file in the main level of the profile folder. If you are planning to switch out that file for an earlier one, make sure to allow a few moments for Firefox to create that file after exiting. Then rename sessionstore.js to sessionstore.old, and copy in recovery.js or previous.js, depending on what you want to try, and rename that to sessionstore.js. Then when you start Firefox, if your session is not resumed automatically, use History > Restore previous session.

I can find previous and restore files but without extension, so I assume they are .js. But I can't find sessionstore.js. The only other files are recovery.bak and three upgrade.js files.

sessionstore.old and sessionstore.bak-datetime are likely leftover from a older Firefox version or update as they are no longer used in current Firefox releases.

Does Firefox create a sessionstore.js file when you close Firefox?

Make sure that you do not run Firefox in permanent Private Browsing mode (Never remember history).

• https://support.mozilla.org/kb/Private+Browsing

• Tools > Options > Privacy > Firefox will: "Use custom settings for history"
• Deselect: [ ] "Always use Private Browsing mode"

In case you use "Clear history when Firefox closes".

• do not clear the Browsing History

• Tools > Options > Privacy > Firefox will: "Use custom settings for history": [X] "Clear history when Firefox closes" > Settings
• https://support.mozilla.org/kb/remove-recent-browsing-search-and-download-history

Note that clearing "Site Preferences" clears all exceptions for cookies, images, pop-up windows, software installation, passwords, and other website specific data.

Yes, I have the settings as you recommended them.

See https://support.mozilla.org/questions/1058179#answer-719758

Can you restart Firefox and get the open tabs back if you use the restart command in the command line of the Developer Toolbar (Firefox/Tools > Web Developer; Shift+F2)?

• https://developer.mozilla.org/Tools/GCLI

This is a more complete response to your post:

caradawn said

I can find previous and restore files but without extension, so I assume they are .js.

Windows hides the .js extension by default. Instead, you would see the file name as recovery with a type of JScript. To turn off hiding of file extensions, see: http://windows.microsoft.com/en-us/windows/show-hide-file-name-extensions

caradawn said

But I can't find sessionstore.js. The only other files are recovery.bak and three upgrade.js files.

Is Firefox running? As mentioned in my earlier post, Firefox creates sessionstore.js when it closes. What I failed to mention is that it deletes the old sessionstore.js after it starts up again. So if Firefox running, it's normal not to find sessionstore.js.

Still trying to figure this out, none of these have solved it yet. Thanks for clarifying that the sessionstore file will not be found if I have Firefox open. Can you explain from your first post, "and copy in recovery.js or previous.js"? I'm not sure what "copy in" means. Thanks.

You can copy a previous.js or recovery.js file to sessionstore.js in the main profile folder to replace the existing sessionstore.js file and make Firefox use this file.

You can also check for previous versions of the sessionstore.js file.

• Right-click: Properties > Previous Versions

• http://windows.microsoft.com/en-US/windows7/Previous-versions-of-files-frequently-asked-questions

Can you explain how to get to these files if I have firefox closed? I understand from previous responses that sessionstore will not show up with firefox open, but I can't type about:config to find them unless I have firefox open. Thanks.

If Firefox is open, or while Firefox is open, use about:support and click the Show Folder button. This launches Windows Explorer in a new window. Leave that window open when exiting out of Firefox.

If Firefox is closed, type or paste this in the start menu search box and press Enter:

%APPDATA%\Mozilla\Firefox\Profiles

At that point, you may see only one folder, or you may see several. You may need to use file modification dates to identify your currently live profile folder.