Symfony2 "This authentication method requires a session error" when checking login

I am trying to implement a simple login form following the instructions in the Symfony book, but I am stuck on login. Whenever I try to log in, I get the error "This authentication method requires a session" created from AbstractAuthenticationListener :: handle. I searched the Symfony and Google book and cookbook but didn't find an answer or even some related problem.

Is this a misunderstanding in the book, or perhaps a misconfiguration of my server?

If you need a code extract, don't mind asking ...

security.yml

security:
  encoders:
    Common\Bundle\UserBundle\Entity\User:
      algorithm: bcrypt
      cost:      10
  providers:
    main:
      entity: { class: CommonUserBundle:User }
  firewalls:
    main:
      pattern:   ^/
      provider:  main
      anonymous: ~
      simple_form:
        authenticator: simple_authenticator
        login_path:   /Connexion
        check_path:   /Connexion/verifier
      logout:
        path:   /Deconnexion
        target: /
      remember_me:
        key:      "%secret%"
        lifetime: 2592000
        path:     /
        domain:   ~

      

        
        
        
      

    

config.yml

  framework:
    secret:    "%secret%"
    fragments: { path: /_fragment }
    router:
      resource: "%kernel.root_dir%/config/routing.yml"
    validation:
      enable_annotations: true
    templating:
      engines: ['twig']
    default_locale: "%locale%"
    http_method_override: true