You aren't using Private Browsing mode as that would prevent opening tabs from the previous session? In case you use "Clear history when Firefox closes". *do not clear the Browsing History *Options/Preferences -> Privacy & Security<br>Firefox will: "Use custom settings for history":<br>[X] "Clear history when Firefox closes" -> Settings *https://support.mozilla.org/en-US/kb/delete-browsing-search-download-history-firefox *clearing "Site Preferences" clears exceptions for cookies, images, pop-up windows, and software installation and exception for password and other website specific data *clearing "Cookies" will remove all selected cookies including cookies with an allow exception you may want to keep ---- Does Firefox update the files in the sessionstore-backups folder ? You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the <b>about:profiles</b> page. *Help -> Troubleshooting Information -> Profile Folder/Directory:<br>Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder *https://support.mozilla.org/en-US/kb/Profiles 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)

I had clear browsing history on. Turned that off and my tabs are now restoring. Thanks