Your ‘logged-in’ status is stored in special cookies&#46; If the cookie is removed, you are logged out&#46; You may be in Private Browsing mode or told Firefox not to remember&#46; Type '''about:preferences#privacy'''<enter> in the address bar&#46; The button next to '''History, ''' select '''Use Custom Settings&#46; ''' Turn off '''Always Use Private Browsing Mode''' Turn on '''Remember My Browsing And Download History''' At the bottom of the page, turn on '''Clear History When Firefox Closes&#46; ''' At the far right, press the '''Settings''' button&#46; Turn on ONLY '''Cache''' and '''Form And Search History''' leaving the others off&#46; '''Macs:''' Make sure you install Firefox properly and that you do not run Firefox from within the DMG (Disk Images) file. https://support.mozilla.org/en-US/kb/how-download-and-install-firefox-mac