Session Manager : Addon|All saved sessions lost because its Legacy Extension Now

Dear Mozillians,

I have saved some sessions using add on called Session Manager. But it is now a legacy Extension and I have no longer access to my old sessions that I saved past several months.

I want all the saved sessions back but I have no Idea how to restore them.Also I have installed alternate add on “tab session manager”.


1 Like

Hi Taneja, Tab Session Manager has an import feature, although I haven’t tried it myself.

Session Manager stored its files in a folder named sessions in your Firefox Profile folder:

If Tab Session Manager cannot import them, I have a tool to extract their contents to a web page of clickable links.

The latest version of the Scrounger assumes a recent JSON format, so if it doesn’t work on a Session Manager file, try the older version:


Hello @jscher2000

Thanks for helping,

I was using Session Manager, I had saved almost 20 sessions manually (so as to see them later).

On the addon website it clearly states that all of the saved sessions would be in “Sessions” folder in profile (There is no such folder), I have a folder named “sessionstore-backups”

I tried using the tool you mentioned for extracting the contents (sessionstore-backup folder) but that was not what I am looking for.

Now I am thinking to downgrade firefox so that legacy extension (session manager) starts working & after saving all the content from extension I’ll update firefox to latest version again.

Please kindly suggest it would work for me or not.

Thank You

The sessionstore-backups folder contains files created by Firefox itself. Did your Firefox perform a Refresh at some point? That would move your old profile folder (including the sessions folder) to your desktop inside an Old Firefox Data folder. If you don’t have that, then perhaps you have backups??

Where is it going to find the old data? That is the first step, finding that sessions folder.

1 Like

I got it, since the sessions folder is missing I can never get my old data back :cry:

I’ll take care from next time onward :sweat_smile:

Thank you

Vào 01:35, T.6, 15 Th3, 2019 Tanejaparvesh via Mozilla Discourse đã viết:

What is your OS?

On MacOS, you could look at Time Machine backups of your profile folder.

On Windows 7-10, you could check old restore points using a program like one of the following that allow you to browse and export out files from an old snapshot of your profile folder – DO NOT USE system restore as that will probably cause more data loss:

You probably need to set Windows to show hidden files and folders in order to get to your profile folder in the restore point:

Step back one level in the file system, to the directory (folder) that contains your profile directory.

From the ‘parent’ view: is there just one profile directory? Or are there sibling directories?

Hi, I am having a similar issue. However, I reverted back to a previous version of Firefox. I attempted to do the Profiles thing, but didn’t see my Sessions.

I am rather Tech Inept, so please reply to me with user-friendly instructions. :laughing:

I am wanting to find and install previous versions of my Sessions, if at all possible. Any help you and others can provide, would be gratefully appreciated!

Thanks in advance!

Were you using the legacy extension Session Manager in Firefox 56 (or earlier), or one of the newer session management extensions that runs in Firefox 57+, or Firefox’s built-in session backup feature?


Oh wait, do you mean ?

Here’s the problem: when you install an extension, Firefox assigns a unique ID, and that ID is used to store the extension’s data. So there is some detective work needed to find the old database if you want to migrate the MySessions data from one profile to another.

What version of Firefox were you using before and what version did you revert to?

Hi, and thanks for your help, first of all.

I was using 87, then it asked me to upgrade to…I think…92, but I can’t remember, then I downgraded back to 87.

However, I am fairly good at detective work, so that’s about the only thing I have in my favor, lol.


This is the Session Manager.

Tab Session Manager , it looks like a green floppy disk.

Hi, is that in your new profile? You’ll see that UUID used for the storage folder:


Since the UUID in the URL is randomized on installation, the value in your old profile likely was different. The question is how best to identify the old storage folder and then try swapping its contents into the new one.

Probably you know how to get into a profile folder, but just in case, the about:profiles page has buttons to open the Root Directory of each one. (Ignore the Local Directory, nothing really valuable in there.)

In your old profile, the prefs.js file may contain the old UUID for Tab Session Manager. There is a preference named extensions.webextensions.uuids which would have that information. It’s hard to read, but it’s general structure is:


The public ID for Tab Session Manager is Tab-Session-Manager@sienori so if you have prefs.js open in a text editor, you should be able to use its Find feature to track down its UUID.