First, very important, please make a backup of all files that start with sessionstore in a safe location, such as your Documents folder.

If the .js extension does not show on your sessionstore.js file (not session.js file), you may want to turn off Windows' hiding of file extensions, at least temporarily. See: http://windows.microsoft.com/en-us/windows/show-hide-file-name-extensions

If sessionstore.js is completely missing, that's very strange. In that case, I suggest exiting Firefox and then renaming sessionstore.bak to sessionstore.js to see whether Firefox can read that file when it starts up again.

There are some techniques for extracting URLs from sessionstore.* files which might be helpful if sessionstore.bak isn't useful.

Regarding your item #2 #3, you normally would check for previous versions on the sessionstore.js file or sessionstore.bak file. You would normally expect to find one as of your last round of Windows updates a week or two ago.

Thank you! I had tried to close my browser window before looking for the sessionstore.js file, but still couldn't find it. But only after I turned on the hidden file extensions did the file appear after I exited firefox. I was able to get my all my tabs back, so thank you @jscher2000!

As an extra pre-caution, I decided to bookmark all my tabs and tab groups to avoid this scare again. All my tabs are backed up using Xmarks, which I trust in its reliability.

It may be useful to see this other thread: https://support.mozilla.org/en-US/questions/1032154 The session restore feature has changed in v33 -- that thread has a description of how it works now. (I too had a problem with losing the session recovery info recently, and it was at about the time of the upgrade to v33, but I didn't record the exact info at the time.)

Hello. I need help with my tabs. What can I say first is that i did myself sessionstore backup file and add this file to my desktop. One day i use FireFox and program crashed. After i turned on FF i saw that my tabs gone. My sessionstore file was 09 day but i lost tabs in 23 day. So many tabs.. From History menu i try use: Restore previous session but this not work because words was gray. I was stupid and i read message about that go to Help > troubleshooting information > show folder. After that i saw files (in folder sessionstore-backups) Recovery, previous, recovery.bak but those files time was changes after i use that help and troubleshooting information method. So after i replace Recovery file and named: sessionstore Firefox open blank page and that troubleshooting window. So if i not open help method i think i was able to recover my tabs.. So what i want to ask.. If there is other option to restore my tabs? In that sessionstore-backups folder is 9 files with name: upgrade.js from this file i can't recover? By the way i thought i can restore my windows to earlier time but restore point give me restore only from 17 day. I add image. I lost tabs 2015-03-23d. 02:29h.

Hi magasx, I'm trying to understand the part about previous.js. That was not helpful because it wasn't an early enough version of your session? In your screenshot it is a very large file, and so is your recovery.js. Did you check the list of closed windows and tabs that appears on the History menu to see whether what you're missing appears there?

Your screen shot shows a 9MB file from March 22nd, it's the last one in the list. To try that file, I suggest copying it to a safe place, and then when Firefox is closed, renaming the current sessionstore.js file to sessionstore.old and copying in the upgrade...js file and renaming it to sessionstore.js. Then when you start Firefox, Restore Previous Session. Does that get you close?

jscher2000, big big thank you. :) I did as you say. I take upgrade file and rename it to sessionstore.js then replace with original sessionstore file and my tabs came home. :) i do not know about this method.. wow.. This thing save my tabs. For the future i will know that. Thanks again Mr. jscher2000. :)

Hello! Sorry I'm in a little panic mode here. My two years of work depend on these tabs I need to recover.

I have Mac Os X 10.10.2 and don't really understand where to search for this sessionstore backup folder. Is there a way to make tabs work again on a Mac?

Here's what happened:

After forcing Firefox to quit and then turning it on again all the tabs that were opened in a previous session became inactive and would load as new/blank tabs without any address in them.

I used to reload Firefox previously and it was acting just fine with showing all of my tabs from the session before the reload. But now all of them are just blank.

Is there a way to make these blank tabs work as previously? Can I somehow restore them? Please help, I have so much important information in these tabs.

Thank you very much!

Hi happychickens, I replied to your question here: https://support.mozilla.org/questions/1055878#answer-713914