If you accidentally closed your previous session, you can press the menu button in the top-right corner of the screen (the three lines) and select Restore previous session.

Hope this helps.

I did, but when the close firefox came up, it made my previous session gone. So, can you maybe look through my history and help me with this?

Please help reply back and find my old history. I did previous, but everytime I opened it on Firefox, it just opens a tab and says open. How do I restore my session and please reply soon!

This is what I meant. Please tell me what to do!

First, I'd try the open with Firefox option. I can't say I've even heard of Firefox saving the session as a file instead of just opening the old session.

Hi Cooldude, as an aside, Mozilla doesn't have your history or access to your computer.

There's no way to directly restore a previous.jsonlz4 file. I have a tool to preview it (convert it to a web page of clickable links). You can drag and drop previous.jsonlz4 or other .jsonlz4 file 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.

To try swapping in an older session history file so Firefox will load it, the standard "manual swap" method is as follows (assuming Firefox is still running):

(1) From inside Firefox, 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" button. This should launch a File Explorer window listing the various files and folders in your profile.

(2) Leaving that window open, switch back to Firefox and Exit, either:

• "3-bar" menu button > "power" button Exit
• (menu bar) File > Exit

Pause while Firefox finishes its cleanup -- a file named sessionstore.jsonlz4 should appear in the folder.

(3) Once Firefox has stopped updating things, while viewing the main level of the profile folder, right-click > Rename sessionstore.jsonlz4 to sessionstoreOLD.jsonlz4

If you see an older sessionstore.js or sessionstore.bak file, move it somewhere else or delete it.

(4) Copy in the other file you want to restore, and rename it with the name appropriate for its format:

• Compressed file such as previous.jsonlz4 => sessionstore.jsonlz4
• Uncompressed file such as previous.js => sessionstore.js

(5) Right-click the sessionstore-backups folder and rename it to sessionstore-backupsOLD to prevent Firefox from using another file in there at startup

(6) Start Firefox and it should read the swapped in sessionstore file and restore whatever was in the substitute file; if you do not have Firefox set to restore your previous windows and tabs automatically, use History > Restore Previous Session

Any luck?

Did you try to place the previous.jsonlz4 file in the main profile folder and rename the file to sessionstore.jsonlz4 to replace the existing sessionstore.jsonlz4 to see whether that makes Firefox use this file ?

Make sure that Firefox is closed.

Did it again. Please fix it please. I need it fixed by today soon when I close it.

I already tried to restore it in previous session, but it doesn't work. So please try to fix my history from before with 400 something pages.

Hi Cooldude, your history data and session history data are local to your computer and support forum volunteers do not have access to it.

If neither of these is available (hidden or grayed out) --

• "3-bar" menu button > Restore Previous Session
• (menu bar) History > Restore Previous Session

-- then check either:

• "3-bar" menu button > Library > History > Recently Closed Windows
• "Library" toolbar button > History > Recently Closed Windows
• (menu bar) History > Recently Closed Windows

Can you get back closed windows that might contain the missing tabs?

- - - -

Also, as always, back up what you have ASAP:

(1) To open your profile folder...

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.

(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
• older something.js files (if Firefox didn't clean them up automatically)

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.