Error UserInterFace - security.yml

security:
    encoders:
        App\AdminBundle\Entity\Users:
            algorithm: sha512
            encode-as-base64: true
            iterations: 10

    providers:
        admin:
            entity: {class:AppAdminBundle:Users, property: username}

    firewalls:
        admin:
            pattern: .*
            form_login:
                check_path: /login_check
                login_path: /login
            logout:
                path: /logout
                target: /
            security: true
            anonymous: true
        public:
            pattern: /.*
            security: false

    access_control:
        - { path: /admin/.*, role: ROLE_ADMIN }
        - { path: /.*, role: IS_AUTHENTICATED_ANONYMOUSLY }