If clearing cookies didn't work properly then it is possible that the cookies.sqlite file that stores the cookies got corrupted. *Rename (or delete) <b>cookies.sqlite</b> (cookies.sqlite.old) and delete other present cookies files like <b>cookies.sqlite-journal</b> in the Firefox profile folder in case the file cookies.sqlite got corrupted. You can use this button to go to the currently used Firefox profile folder: *Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder) *http://kb.mozillazine.org/Profile_folder_-_Firefox *http://kb.mozillazine.org/Cookies *https://support.mozilla.org/kb/Deleting+cookies ---- You can try to clear the cache folder on the hard drive manually. You can find the location of the disk cache on the <b>about:cache</b> page. you can open <b>about:</b> pages via the location/address bar.