Hi centeron, have you already tried:

• "3-bar" menu button > Library > History > Recently Closed Windows
  (and within each restored window, Recently Closed Tabs)
• "Library" toolbar button > History > Recently Closed Windows
  (and within each restored window, Recently Closed Tabs)
• (menu bar) History > Recently Closed Windows
  (and within each restored window, Recently Closed Tabs)

Back up 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 > "?" Help > 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 "Open Folder" (or "Show in Finder") 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, double-click into the sessionstore-backups folder. Save all files here to a safe location such as your Documents folder.

(3) What files did you find?

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

• recovery.jsonlz4: 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.baklz4: a backup copy of recovery.jsonlz4
• previous.jsonlz4: the windows and tabs in your last Firefox session
• upgrade.jsonlz4-build_id: the windows and tabs in the Firefox session that was live at the time of your last update
• possibly some .js files from Firefox 55 or earlier

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 the missing tabs?

To preview the contents of a file, you can drag and drop it onto this page, then click Scrounge URLs: https://www.jeffersonscher.com/ffu/scrounger.html

That tool is on my site, so please let me know if it doesn't work for you.

not getting it. ur first 3 options have u already tried: all i get up seems is just the current windows - i guess they r 3 different options leading to same place? do not see restored window, then recently closed tabs thereafter.... As to open ur profile folder ive gone that rout and clicked on open folder and reached some json files but not sure what to do after that and there is no : AND comments as u have after each when i try to open one i do not know which app to use and just get gublyglop letters

Files with lz4 are compressed. You can't view them in any application. That is why I created the Scrounger page.

could not find a save file option on those 6 or so json. also could not coppy or paste. also not sure how to drag it and do u mean onto this page right here or onto another tab with ur jeffersonscher. i also assume that each file must go over individually one at a time. so many unsures here for me. thks

Hi centeron, if you open this page:

https://www.jeffersonscher.com/ffu/scrounger.html

You'll see a large white area to drop the file on. Then you can click the Scrounge URLs option to list out the tabs in the file. To check a different file, reload the page (Ctrl+r) and drop the other file and Scrounge.

Can you find one that has what you want?

Jefferson still cannot get one of the files over after i click on the sessions thing and see about 6 jsron file - i try copy and paste and nothing happens so that is only way i translate the word Drop. Cannot seem to get there with browse either thks for ur continued effort.

ie not one of 6 over at all

To drag and drop, you make the File Explorer window about 1/4 screen so you can see the white box where you want to put the file. Then click and hold on the .jsonlz4 file and drag across and release on the white box.

are u talking about the blank space inside the history scrounger so it is i/4 size? it does not come up when i am on that page but my general index comes up. Yesterday i managed to drop one of the files into the box but it came up gugiglop. Is there something i have to do on the scrounger after i drop and some script appears to get it to simple readible? Also in the process i now have openned guess about 8 windows in firefox so wondering if the whole process aint going to work and would be better off just going thru the months of history and looking for individual tabs i want to rerieve even tho that will be time consumiing. thks

Hi centeron, If you have closed more than 3 windows in your current session, then your current session files won't be useful for recovering closed windows (only 3 are retained, unless you changed that setting before). However, you still could look at older copies of your session history files that you backed up.

Yesterday i managed to drop one of the files into the box but it came up gugiglop.

The box normally starts with text like this:

{"version":["sessionrestore",1],"windows":[{"tabs":[{"entries":[{"url":"about:home","title":"New Tab",

Of course the page in your first tab will vary.

Then click the Scrounge URLs button below the box to extract that into a readable format.