Make sure that you not run Firefox in "Private Browsing" mode. In Private Browsing mode some menu items are disabled (grayed) and some features like visited links and others are disabled and not working. You are in Private Browsing mode if you see "Tools > Stop Private Browsing" See [[Private Browsing]] and http://kb.mozillazine.org/Issues_related_to_Private_Browsing ..... You enter Private Browsing mode if you select: Firefox > Preferences > Privacy > History: Firefox will: "Never Remember History" To see all History settings, choose: Firefox > Preferences > Privacy, choose the setting '''Firefox will: Use custom settings for history''' Uncheck: [[ ] "Automatically start Firefox in a private browsing session" ---- Menu differences: [http://kb.mozillazine.org/Menu_differences Windows: Tools > Options - Mac: Firefox > Preferences - Linux: Edit > Preferences]