If you don't see any options under History from the menu try this. With Firefox closed, you're taking one files from the sessionstore-backups folder (with a date before the issue happened and bigger size) and moving it to the profile directory which should be 1 folder up and then renaming it to sessionstore.jsonlz4. see screenshot

Is there really valid session data in this file as the name you posted doesn't look very promising to me? In what location did you find this file?

I notice that you posted with you posted with an outdated Firefox 109.0.1 version. Any special reason for not updating?

• https://support.mozilla.org/en-US/kb/update-firefox-latest-release
• https://www.mozilla.org/en-US/firefox/123.0.1/releasenotes/

jonzn4SUSE I only have three files in my sessionstore-backups folder. They are all dated today

-(

Cor-el I went here https://www.jeffersonscher.com/ffu/scrounger.html. I found a "sessionstore.nsonlz4" from 1-11-23 and drug it into the scrounger. Under HTML List Commands I clicked "Scrounge URLs" This then revealed "Session History" which showed my lost tabs. Satisfied, I clicked on "JSON file: Save Uncompressed JSON (sessionstore.js format)" It downloaded "sessionstore(sessionstore_jsonlz4).json" a 20,740KB file. What should I do next?

You do not really need this uncompressed .json file. All you need to do is to place this file as sessionstore.jsonlz4 at the main profile folder level where sessionstore-backups is located to replace the sessionstore.jsonlz4 created by Firefox. Firefox needs to be closed as only then sessionstore.jsonlz4 will be present.

That did it! Thank you so much. What a relief.