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sessionstore.js cannot be found in 33.1.1

  • 16 replies
  • 17 have this problem
  • 5 views
  • Last reply by ptressel

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I depend on Group Tabs and if/when FireFox crashes sometimes sessionstore.js gets corrupted. I regularly archive copies of that file so I can recover. In one of the latest versions (after 11/8/2014) it appears that you have either changed the method or hidden sessionstore.js somewhere other than on my C:/ drive. it is no longer "findable" with "show hidden files" turned on

1. Will you tell me/us where it is now located or 2. Tell me/us how to recover our sessions

I depend on Group Tabs and if/when FireFox crashes sometimes sessionstore.js gets corrupted. I regularly archive copies of that file so I can recover. In one of the latest versions (after 11/8/2014) it appears that you have either changed the method or hidden sessionstore.js somewhere other than on my C:/ drive. it is no longer "findable" with "show hidden files" turned on 1. Will you tell me/us where it is now located or 2. Tell me/us how to recover our sessions

All Replies (16)

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If anyone is interested here is the content of my ff.bat file

copy C:\Users\Gerry\AppData\Roaming\Mozilla\Firefox\Profiles\moxsr768.default\sessionstore.js D:\SessionStoreArchives\sessionstore-%1.js DIR D:\SessionStoreArchives\*.js

calling sequence (example) ff 2014.11.20

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The sessionstore.js file is still located in the Firefox profile folder. Current Firefox releases also keep a backup of sessionstore files in the sessionstore-backups folder to recover from issues with saving a new copy of the sessionstore.js file. The upgrade.js files with a build ID appended in that folder are created when Firefox is updated.

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

  • Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
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Thanks... I did the above (troubleshooting info folder) and it does take me to the same folder where I used to locate sessionstore.js. In my case it is: C:\Users\Gerry\AppData\Roaming\Mozilla\Firefox\Profiles\moxsr768.default\

Inspecting that folder, there is no file called sessionstore.js in it. Inspecting the /sessionstore-backups folder, there is no sessionstore.js in it (or any variation of that name) but there are two files ... recovery.js & and recovery.bak. plus 3 other files previous.js & two apparent time-stamped named files upgrade.js*.js-*

I again searched my whole C:/ drive and there is no file named sessionstore.js.

Am I missing something here?

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FF crashed while scrolling down a page (mostly text), then crashed on restart TWICE! My problem is, where has sessionstore.js got to. I had to use one from some weeks ago to try to recover session as I want it, with obvious losses. (.bak is 3 weeks old, but I managed to get a copy of .js a couple of weeks ago.) I can restore an old version of sessionstore.js, but as soon as FF opens the sessionstore.js disappears from the folder. Clearly FF is using it, but losing it! Then, when FF crashes, as it does too often on opening, sessionstore.js is not there to do the next restore. Initially, it would get renamed to sessionstore.bak, but that doesn't happen now. A vital tool to help restoration from crashes doesn't work now!

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I have 3 FF windows, each with a number of tabs. One opened properly with a restored version of sessionstore.js, from a restore point, but two had a series of New Tabs, although entering text in the url bar would jump to a 'hiddden' tab. Strange, seems to be partly but not completely there!

I've found the sessionstore-backups folder, but how do I use the files in it to create a new sessionstore.js file?

Modified by henryfm

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I'm still waiting for the original responder to give us feedback. Clearly sessionstore.js IS NOT in the folder.

However, I noticed that you use sessionstore.bak to recover ... I have found that when sessionstore.js gets corrupted that sessionstore.bak is also of no use. That is why I use a batch file to backup sessionstore.js whenever I have a configuration I don't want to lose (remember, I am using Group Tabs).

Again, here is the backup batch file that I use: it creates a file with the bat file's calling argument e.g. my batch file is called ff.bat & I call it with the current date as an argument ..

ff 2014.11.24

This creates a copy in the directory specified in the batch file called sessionstore-2014.11.24.js


copy C:\Users\Gerry\AppData\Roaming\Mozilla\Firefox\Profiles\moxsr768.default\sessionstore.js D:\SessionStoreArchives\sessionstore-%1.js DIR D:\SessionStoreArchives\*.js

calling sequence (example) ff 2014.11.20

Modified by GerryWilliams2

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Hi Gerry

The screenshots do not show the file dates of the files in the sessionstore-backups folder, so I don't know if those are recent. I do notice a zzzsessionstore.js file in the first screenshot.


Session data is still stored in the sessionstore.js file in the profile folder. The sessionstore.bak file is no longer used and has been replaced by the recovery and previous files that you find in the sessionstore-backups folder. The upgrade files in this folder with the build ID appended are created when Firefox is updated.

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a) Why isn't the sessionstore.js file visible in the Profile folder (FF running normally or when closed/crashed), other than for a few seconds I think after starting? b) what do you mean by 'when Firefox is updated'? When you upgrade from 33 to 33.1 to 33.1.1 ? c) How do you use the backup files to restore, especially if an attempted restart fails (twice)?

Modified by henryfm

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Respectfully, sessionstore.js is not on my C:/drive, in any directory. If you will look at the initial thread, you will see others who cannot find it either.

The /sessionstore-backups/ has files (recovery.js, recovery.bak & previous.js) that are the right size for my missing sessionstore.js file. However, there are no new (current) files in the PROFILES folder. Only my backup file from 11/1 (zzzsessionstore.js) and the old FF backup file (sessionstore.bak) from 11/6.

If it will help, I will be willing to share my screen with you via Skype (cadre.gjw)

Thanks, Gerry

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Why is nobody answering this question? How is the new version of Firefox restoring sessions without the sessionstore.js file in the profiles folder?

Someone has to know the answer!!!!!! Please help us out!!!!!!!!

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My understanding is that the /sessionstore-backups/ folder has the file recovery.js which is a copy of the phantom sessionstore.js file (phantom because you can't see it!!). The .bak is a slightly older version, recovery.js somewhat older. Not seen any explanation of why, maybe that FF has to start properly before writing to recovery.js, whereas ss.js can get corrupted very quickly

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GerryWilliams2 said

I depend on Group Tabs and if/when FireFox crashes sometimes sessionstore.js gets corrupted. I regularly archive copies of that file so I can recover. In one of the latest versions (after 11/8/2014) it appears that you have either changed the method or hidden sessionstore.js somewhere other than on my C:/ drive. it is no longer "findable" with "show hidden files" turned on 1. Will you tell me/us where it is now located or 2. Tell me/us how to recover our sessions

I'm having a similar problem. There is NO sessionstore.js in my Profiles folder, even after I first rename a backup to sessionstore.js and copy it into said folder. Firefox seems to delete it?? I've lost access to my tab groups and am looking for a means to restore them.

I also think there ought to be a way to backup and restore tab groups similar to how one does this with bookmarks from the Bookmarks menu. Otherwise, it's a bad thing to rely on Tab Groups in Firefox - unreliable, it seems.

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Gerry, et al. --

I, too, depend on making out-of-band copies of the session file or session backup file, as it is sometimes truncated to (almost) empty. (Possible causes of this truncation are a separate issue, but include 1) something unknown but about the time of the Firefox upgrade referenced below, and 2) other apps that start my browser and open pages.)

It appears the change we're seeing was made in v 33.0 -- here are the release notes and the blog post (linked from the release notes) describing the change: https://www.mozilla.org/en-US/firefox/33.0/releasenotes/ https://dutherenverseauborddelatable.wordpress.com/2014/06/26/firefox-the-browser-that-has-your-backup/

From that blog post (both what it says explicitly and from reading between the lines), and from watching the files change as Firefox is shut down and restarted, and as tabs are opened / closed, the following appears to be the new order of events. Caution -- I did not look at the actual code to verify this, so would be good to have confirmation. All paths in the following are relative to the profile directory.

  • The actual current session is in memory only -- this facility is referred to as "Session Restore" in the blog post.
  • When Firefox starts, it looks for sessionstore.js in the profile. If that exists and is valid, it is read into the Session Restore facility *and* copied to sessionrestore-backups/previous.js.
  • It then *deletes* sessionstore.js. This happens *before* the user does History -> Restore Previous Session. Thus sessionstore.js does not exist while Firefox is running.
  • When there is a change in the session (including startup), but limited to once per 15 seconds, sessionrestore-backups/recovery.js is renamed to sessionrestore-backups/recovery.bak and the current session is written to sessionrestore-backups/recovery.js.
  • When Firefox is shut down, it writes the session to sessionstore.js.
  • Before an upgrade, Firefox saves the session to sessionrestore-backups/upgrade.js-<build-id>.

So, Gerry, it sounds like you should change your script to make copies of all three files, if they exist:

  • sessionstore.js
  • sessionrestore-backups/recovery.js
  • sessionrestore-backups/recovery.bak

And it would be good to wait > 30 seconds without any session activity in Firefox before running it -- that will allow time for changes to the two recovery files to be done.

(I should mention...if one wants to be *really* safe about session recovery, there's transaction logging, just like database management systems do. It does impose a time / disk overhead, so there's risk / benefit to be considered.)

Modified by ptressel

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Found another thread on this subject -- there's a good answer over there: https://support.mozilla.org/en-US/questions/1028115

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Hello, ptressel:

Thank you for your leg work on summarising the mechanism that Firefox currently handles the session. I had a problem and asked about it, but had no replies in a couple days. As I do some programming, I tried to dig more and found your article here. It gave me the information that I needed to solve the problem.

There are a couple things I would like to add for anyone who might stumble upon this:

  1. I was trying to recover the session from my Windows Home Server, which has given me better backups than I've ever had, but it does this while I'm using the computer (and Firefox) so the sessionstore.js file never exists at the time of backup. I thought I would mention that for anyone else recovering from Windows backups, or perhaps any other.
  2. I think you mean in your reply of 1/4/15 6:53pm, sessionstore.js, not sessionrestore.js, and sessionstore-backups, not sessionrestore-backups, unless that reflects a name change betwee v33 and my v36.

Thanks again!

Modified by Mike

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You're right, em-squared, thanks for noting that the name of the file was misspelled! I saw that but didn't think there was a way to update the post. I just now noticed the "edit" button next to it.  :D (I may not have been logged in, I suppose...) Anyhow, fixed it.

I've had to fetch these from my cloud backup a couple of times -- I get the recovery.js and previous.js files out of the sessionstore-backups -- or just from the local disk. (The latter has mainly happened when something goes haywire and Firefox gets hung in a CPU-bound state, menus become unresponsive, and I have to kill it via Task Manager, so the sessionstore.js file is not created.)

Modified by ptressel