First check the settings and try all of the options in the [[websites say cookies are blocked]] article. In addition to the above, another possible cause is the file that stores cookies is corrupt, if that is the case deleting the file should fix the problem. First you need to locate your profile folder, for details of how to do that see the [[profiles]] article. Once you have opened the profile folder, close Firefox and either delete or rename cookies.sqlite, when you restart Firefox that file will be re-created.