If your users are unable to log in to sites using the Basic SSO apps or plug-ins, have the users delete the credentials stored for that site. Users can delete their own credentials from the landing page.
This problem arises when a site uses two different HTML forms or changes fields on the same HTML form during the login or password change process.
Having the users delete their stored credentials from the appliance allows the Basic SSO app or the plug-in to save the new credentials.