Try this: Click on the "open menu" icon at the upper right of your browser window (looks like 3 horizontal bars), the click "history". The 4th option down is "restore closed tabs." Does this still open blank tabs, or did it work for you?

Let's back up your existing session history files. Do not exit Firefox, or if you closed it, don't re-open it.

(1) To open your profile folder...

If Firefox is still running:

You can 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.

If Firefox is closed:

Type or paste the following into the Windows Run dialog or the system search box and press Enter to launch Windows Explorer:

%APPDATA%\Mozilla\Firefox\Profiles

In that folder, do you see a semi-randomly-named folder? If so, click into it. If you find multiple such folders, find the one that was most recently updated.

(2) Copy out session history files

In your profile folder, scroll down and double-click into the sessionstore-backups folder. Save all files here to a safe location, such as your Documents folder. If not too much time has passed, we may be able to use them to recover your lost tabs.

(3) What files did you find?

The kinds of files you may find among your sessionstore files are:

• recovery.js: the windows and tabs in your currently live Firefox session (or, if Firefox crashed at the last shutdown and is still closed, your last session)
• recovery.bak: a backup copy of recovery.js
• previous.js: the windows and tabs in your last Firefox session
• upgrade.js-build_id: the windows and tabs in the Firefox session that was live at the time of your last update

Could you take a look at what you have and the date/time of the various files to see whether you think any of them would have most or all of the missing tabs?

Note: By default, Windows hides the .js extension. To ensure that you are looking at the files I mentioned, you may want to turn off that feature. This article has the steps: http://windows.microsoft.com/en-us/windows/show-hide-file-name-extensions

Leah said

Try this: Click on the "open menu" icon at the upper right of your browser window (looks like 3 horizontal bars), the click "history". The 4th option down is "restore closed tabs." Does this still open blank tabs, or did it work for you?

Your reply is much appreciated!

I just tried what your suggested but I'm still seeing about 90% of my tabs as "New Tab" at the top of each tab... :'(

Also, if the session history file is only slightly damaged, it often is possible to pull out all the URLs into a plain list which you then could use to open the tabs again. The more tabs, the more trouble this is, but for future reference in case it's needed, see this thread: https://support.mozilla.org/en-US/questions/1129318#answer-893012

jscher2000 said

Let's back up your existing session history files. Do not exit Firefox, or if you closed it, don't re-open it. (1) To open your profile folder... If Firefox is still running: You can 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. If Firefox is closed: Type or paste the following into the Windows Run dialog or the system search box and press Enter to launch Windows Explorer: %APPDATA%\Mozilla\Firefox\Profiles In that folder, do you see a semi-randomly-named folder? If so, click into it. If you find multiple such folders, find the one that was most recently updated. (2) Copy out session history files In your profile folder, scroll down and double-click into the sessionstore-backups folder. Save all files here to a safe location, such as your Documents folder. If not too much time has passed, we may be able to use them to recover your lost tabs. (3) What files did you find? The kinds of files you may find among your sessionstore files are:

• recovery.js: the windows and tabs in your currently live Firefox session (or, if Firefox crashed at the last shutdown and is still closed, your last session)
• recovery.bak: a backup copy of recovery.js
• previous.js: the windows and tabs in your last Firefox session
• upgrade.js-build_id: the windows and tabs in the Firefox session that was live at the time of your last update

Could you take a look at what you have and the date/time of the various files to see whether you think any of them would have most or all of the missing tabs? Note: By default, Windows hides the .js extension. To ensure that you are looking at the files I mentioned, you may want to turn off that feature. This article has the steps: http://windows.microsoft.com/en-us/windows/show-hide-file-name-extensions

Wow! jscher2000, your detailed reply is really appreciated.

I just did as you said:

The date "recovery.js" was created was ‎Sunday, ‎17 ‎April ‎2016, ‏‎2:38:42 PM

The date "recovery.bak" was created was ‎Sunday, ‎17 ‎April ‎2016, ‏‎2:38:42 PM

The date "previous.js" was created was ‎Tuesday, ‎22 ‎March ‎2016, ‏‎8:46:47 PM

By the way, when I say 90% of the tabs I had opened are gone the number of tabs that are gone is around 280 tabs I had opened I was using...

It'd REALLY mean a lot to me if we could get them back... :( :( :(

Please let me know if you need any more information!

By the way, when I say 90% of the tabs I had opened are gone the number of tabs that are gone is around 280 tabs I had opened I was using...

Forgive me for "rubbing salt into the wound" but that is just plain asinine to trust the default session restore to save that many tabs "many times".

It may have worked for you when you were able to "Exit" Firefox properly, but having to "force" Firefox to close using { Ctrl + Alt + Del } may have been because Firefox was "hung" and "all bets are off" when C-A-D is used. A good part of the "tab saving" process is done during a proper "Exit".

Sorry, I can't help you beyond recommending that you look into a "session manager" extension to help you lessen the chance of that happening again! And maybe run fewer tabs and more windows. AMO search for "session"

Hey man, reading your reply has really upset me especially when my emotional state is already low after losing so many tabs I was working on.

Is there any hope for me to somehow re-gain the tabs I lost...?

Hi newbie333,
Please tell me that   '280'  was a typo;   otherwise you'd still have   28   tabs left ,   and even that's a lot of tabs  !
I can see that you're in a real emotional state and,   believe me;   I understand .....
Now,   try to relax;   sit down and make a list of those tabs that are  really important   to you and just re-create them   ......   how does that sound   ?
Good luck    !

Sorry that I offended you, but if the files that jscher2000 mentioned, that you found are that old, there really isn't any way to recover data isn't there any longer. And I suggested using an extension to "extend" the basic feature that is built in to Firefox to help keep that from happening again.

You answered jscher2000 first posting, but not the 2nd. And you belatedly providing the information about 280 tabs being lost, that 2nd bit of information he provided is useless when it is beyond 3 closed windows and 10 closed tabs per window. I very carefully read all that had transpired (including what he wrote in that other thread) and I only stepped in when when it looked like to were getting impatient waiting for him to respond to you. I happen to know the time zone he is in and figured he wouldn't be back for at least another 8 hours or more.

You have to keep in mind that he and I, along with most of the other support contributors around here are merely other users (like you) who volunteer their time to help you. Few of the Mozilla personnel ever "work" the support fora and those that do are here mostly during "business hours" PDT and those that do IMO wouldn't have been able to provide the information that jscher2000 gave you.. And using volunteer users to provide support to other users is the norm with most Open Source software projects, and even with many "pay to play" software companies these days have much of their support done by other user volunteers when they use forums.

Hi newbie333, I'm definitely puzzled by the file creation dates. That said, the file modification date is more important than the creation date. If recovery.js does not show it was updated yesterday, I wonder whether you were copying files from the correct folder. Or whether your system clock is running about 3 months behind? Or whether the Windows "system restore" feature might have rolled back the files?

Could you try the URL extraction technique with the recovery.js file, as described in: https://support.mozilla.org/questions/1129318#answer-893012

is there only one profile folder if you go up one level?

• C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\

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

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

Do you have an "Old Firefox Data" folder on the desktop in case you used the refresh feature in Firefox?

You can check in Windows Explorer if there is a previous version of the sessionstore.js file available.

• Right-click: Properties -> Previous Versions
• http://windows.microsoft.com/en-us/windows-8/how-use-file-history

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

• Help -> Troubleshooting Information -> Profile Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox