Is History > Restore Previous Session grayed out, or can you use it? ---- Could you check these settings on the Preferences page: (1) Startup: is it set to "Show your windows and tabs from last time"? See: [[Startup, home page, tabs, and download settings]] (2) History: make sure Firefox isn't using automatic private browsing or clearing history at shutdown. On the Privacy panel, right side, you should have either: * Firefox will: Remember history * Firefox will: Use custom settings for history, with ** check mark for "Remember my browsing and download history" ** either no check mark for "Clear history when Firefox closes" or if it is enabled, when you click the Settings button to the right, "Browsing & Download History" is NOT checked ---- Is Firefox saving session history in real time? You can check that by opening your current Firefox settings (AKA Firefox profile) folder. Either: * "3-bar" menu button > "?" button > 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 Directory" button. In your profile folder, scroll down and double-click into the '''sessionstore-backups''' folder. The kinds of files you may find here include: * recovery.js: 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.bak: a backup copy of recovery.js * previous.js: the windows and tabs in your last Firefox session * upgrade.js-''build_id'': the windows and tabs in the Firefox session that was live at the time of your last update If you have numbered files like recovery-1.js, Firefox is having problems writing to recovery.js which will prevent you from restoring your latest session (or possibly any session).