On 6/22/2021, after updating mozzila browser, all my previously open tabs and the ability to revert to the previous session disappeared. The cards contained very important information for me, so I am asking if it is possible to restore these cards by, for example, a mozzila employee?
Maybe you have a upgrade.jsonlz4-<build_id> file in the sessionstore-backups folder that has the lost tabs. You can look at this tool to inspect a compressed sessionstore file.
Backup the session files in the sessionstore-backups folder in the Firefox profile folder to make sure not to lose possible important session data. Do NOT close Firefox when Firefox is already running.
You can use the button on the "Help -> More Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.
- Help -> More Troubleshooting Information -> Profile Folder/Directory:
Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder
You will normally find these files in the sessionstore-backups folder:
- previous.jsonlz4 (cleanBackup: copy of sessionstore.jsonlz4 from previous session that was loaded successfully)
- recovery.jsonlz4 (latest version of sessionstore.jsonlz4 written during runtime)
- recovery.baklz4 (previous version of sessionstore.jsonlz4 written during runtime)
- upgrade.jsonlz4-<build_id> (backup created during an upgrade of Firefox)
You can copy a file from the sessionstore-backups folder to the main profile and rename the file to sessionstore.jsonlz4 to replace the current file with Firefox closed.
- make sure to backup the current sessionstore.jsonlz4