Are you able to restore your previous session manually using the menu? Either: * "3-bar" menu button > History > Restore Previous Session * (menu bar) History > Restore Previous Session If they are missing or grayed, check either: * "3-bar" menu button > History > Recently Closed Windows * (menu bar) History > Recently Closed Windows Anything there? ---- One possible reason for not being able to restore a previous session is if Firefox is set to not record browsing history. If you switch over to: Settings/Preferences page > Privacy & Security panel and scroll down to the History section, the following will cause problems with restoring your previous session -- these are not compatible with session restore: * Firefox will: Never remember history * Firefox will: Use custom settings for history AND the box for "Always use private browsing mode" is checked * Box for "Remember browsing and download history" is not checked * Box for "Clear history when Firefox closes" is checked AND when you click Settings, "Browsing & download history" is checked