Symfony authentication (You cannot refresh a user from the EntityUserProvider)

Question

After authentication , when I enter the right username/password I'm redirected to a new page ( driverspace/dashboard ) with this error :

You cannot refresh a user from the EntityUserProvider that does not contain an identifier.
 The user object has to be serialized with its own identifier mapped by Doctrine.

And the symfony bar shows : "You are not authenticated" ..

Here my security.xml firewalls:

    driver_firewall:
        pattern: ^/driver
        form_login:
            provider: user_db
            login_path: /driver/login
            check_path: /driver/login_check
            remember_me: true
            always_use_default_target_path: false
            default_target_path:            /driverspace/dashboard
            target_path_parameter:          _target_path
            use_referer:                    false
        logout:
            path: /driver/logout
            target: /
        remember_me:
            key: MiPassphrase
            lifetime: 1800
            path: /.*
            domain: ~
        security: true
        anonymous: true
    main:
        pattern: ^/
        form_login:
            provider: fos_userbundle
            csrf_provider: form.csrf_provider
        logout:       true
        anonymous:    true

PS : I have 2 Type of user , so i worked with fos to manage one and the basic authentication to manage the other , EDIT : Driver ENTITY

class Driver extends BaseUser implements \FOS\UserBundle\Model\UserInterface
{
    /**
     * @var integer
     *
     * @ORM\Column(name="id_driver", type="integer", nullable=false)
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="IDENTITY")
     */
    private $idDriver;

    /**
     * @var string
     *
     * @ORM\Column(name="fname_drive", type="string", length=30, nullable=false)
     */
    private $fnameDrive;

    /**
     * @var string
     *
     * @ORM\Column(name="lname_driver", type="string", length=30, nullable=false)
     */
    private $lnameDriver;

    /**
     * @var string
     *
     * @ORM\Column(name="phone_driver", type="string", length=15, nullable=false)
     */
    private $phoneDriver;

    /**
     * @var float
     *
     * @ORM\Column(name="lat_driver", type="float", precision=10, scale=0, nullable=true)
     */
    private $latDriver;

    /**
     * @var float
     *
     * @ORM\Column(name="lon_driver", type="float", precision=10, scale=0, nullable=true)
     */
    private $lonDriver;

    /**
     * @var integer
     *
     * @ORM\Column(name="activenow", type="integer", nullable=true)
     */
    private $activenow;

    /**
     * @var \Company
     *
     * @ORM\ManyToOne(targetEntity="Company")
     * @ORM\JoinColumns({
     *   @ORM\JoinColumn(name="company_id", referencedColumnName="id_company")
     * })
     */
    private $company;

    /**
     * @var \Doctrine\Common\Collections\Collection
     *
     * @ORM\ManyToMany(targetEntity="Car", inversedBy="idDriver")
     * @ORM\JoinTable(name="driver_car",
     *   joinColumns={
     *     @ORM\JoinColumn(name="id_driver", referencedColumnName="id_driver")
     *   },
     *   inverseJoinColumns={
     *     @ORM\JoinColumn(name="id_car", referencedColumnName="id_car")
     *   }
     * )
     */
    private $idCar;

Answer 1

I solved the problem by :

1- Changing idDriver to id , because the driver class extends BaseUSer

2- adding :

 public function serialize() {
    return serialize($this->id);
    }

    public function unserialize($data) {
    $this->id = unserialize($data);
    }

I hope this solution will help someone