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"Recently closed tabs" and "Restore previous session" do not work.

  • 5 replies
  • 24 have this problem
  • 5711 views
  • Last reply by belac1

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I am using Firefox 30.0 on a Mac. I know exactly where to go to find the "restore previous session" and "recently closed tabs" list, and they still appear to be present, but I can not click on them. However, all history is still being recorded. I've found several people having similar problems, and the solution to the problem closest to what I am experiencing recommended going to about:config and checking to make sure that browser.sessionstore.enabled was present. I did so, and it was not, so I followed the instructions in that thread and added it. I restarted firefox, but it didn't work. SO I went back to the thread, and farther down it said that I needed to check/add browser.sessionstore.max_tabs_undo and browser.sessionstore.max_windows_undo I did this too, and restarted firefox again. Still nothing. All the settings for these were set to the defaults. Suggestions?

All Replies (5)

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For reference, the earlier thread is here: https://support.mozilla.org/questions/984786

Could you provide a little more information:

(1) Do you have Firefox set to start up with your previous session windows and tabs, or are you trying to restore the earlier session manually from the History menu (or built-in Firefox home page)?

  • If Firefox is set to start up with your previous session windows and tabs, then it is normal for Restore Previous Session to be grayed out.
  • A user.js file, which overrides your normal settings, also can command Firefox to resume the previous session. To check for such a file and remove it if you find it, try the steps in this article: How to fix preferences that won't save.

(2) Is Firefox tracking closed tabs during your session? To check on that, you can close a tab in the window, and then check either:

  • "3-bar" menu button > History - titles of closed tabs are listed below the "Restore Closed Tabs" heading (clicking that heading will restore ALL of them, so don't click that heading)
  • (menu bar) History > Recently Closed Tabs - titles of closed tabs are listed on a fly-out menu

(3) Similarly, is Firefox tracking closed windows during your session?


If Firefox tracks session history during your session but all that history is lost when you exit Firefox, there are several possible explanations.

One possibility is that Firefox is using a temporary sessionstore file because the main file is locked or corrupted. You can check on that by viewing the sessionstore files in your currectly active Firefox profile folder. To open that folder, either:

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

In the first table on the page, click the "Show in Finder" button.

When the Finder window loads, scroll down and look for all file names starting with sessionstore. These typically include:

  • sessionstore.js - should be your current session windows and tabs
  • sessionstore.bak - should be your previous session windows and tabs
  • sessionstore.bak-datetime - should be your windows and tabs at the time of your last update

If you find files that have a number in the left part of the name, such as sessionstore-1.js, this usually indicates that Firefox is not able to update sessionstore.js. If you can see that sessionstore-number.js is the most recently, then you can (after completely quitting out of Firefox), delete the old sessionstore.js and rename the most recent numbered file to sessionstore.js.

Not sure whether that is relevant in your case.

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On Mac you may have to make sure to close the Firefox application (Firefox > Quit) while the window with the tabs is still open. If you close all open windows and then close Firefox then Session Restore may not work properly.

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  1. Firefox is set to reopen with the tabs and windows from my last session.
  2. Following the instructions, I was unable to find the user.js file.
  3. Firefox is NOT tracking my tabs, in either the "3-bar" or menu bar. However, it is tracking the actual sites I visit in the "All History" area. It just doesn't seem to recognize that they're different tabs.
  4. When I close Firefox, I am not closing individual tabs and windows first. I am quitting the application while all the tabs and windows are still open.
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Is there a sessionstore.js file created in the Firefox profile folder?

You can check browser.sessionstore.* prefs including browser.sessionstore.resume_from_crash on the about:config page and reset browser.sessionstore prefs that are user set (bold) via the right-click context menu to the default value to make sure that Session Restore is enabled and working properly.


You can check for problems with the sessionstore.js and sessionstore.bak files in the Firefox profile folder that store 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).

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There is a sessionstore.js file, as well as a sessionstore.bak file and sessionstore.bak-datetime file. There is no sessionstore-number.js file. I searched for "sessionstore" on the about:config page, and reset all of the results to the default. I then quit Firefox and restarted it. The problem is still not solved. Also, in answer to an earlier question, Firefox is NOT tracking closed windows during the session either.