title: Could not load type "sonata_user_registration"
body: <p>When i try override the registration form in SonataUserBundle i got this error : "Could not load type "sonata_user_registration"".I searched the solution of this problem but any of them doesn't help me. I successfully override template but now, I need override registration form(add age field), so I added  few code in </p>
  
  <pre><code>//app/Application/Sonata/UserBundle/Entity/User.php
    /**
       * @ORM\Column(type="string", length=255)
       *
       * @Assert\NotBlank(message="Please enter your name.", groups={"Registration", "Profile"})
       */
      protected $age;
  
  
          public function getAge()
      {
          return $this-&gt;age;
      }
  
          public function setAge($age)
      {
           $this-&gt;a=$age;
      }
  </code></pre>
  
  <p>But if i  run php app/console doctrine:schema:update --force it told nothing to update
  My RegistrationFormType:</p>
  
  <pre><code>  //app/Application/Sonata/UserBundle/Form/Type/RegistrationFormType.php
  namespace Application\Sonata\UserBundle\Form\Type;
  
  use Symfony\Component\Form\FormBuilderInterface;
  use FOS\UserBundle\Form\Type\RegistrationFormType as BaseType;
  
  class RegistrationFormType extends BaseType
  {
      public function buildForm(FormBuilderInterface $builder, array $options)
      {
          parent::buildForm($builder, $options);
          $builder-&gt;add('age');
      }
  
      public function getName()
      {
          return 'sonata_user_registration';
      }
          public function getParent()
      {
          return 'fos_user_registration';
      }
  
  }
  </code></pre>
  
  <p>My services.yml:</p>
  
  <pre><code>//app/Application/Sonata/UserBundle/Resources/config/services.yml
  services:
      sonata_user.registration.form.type:
      class: Application\Sonata\UserBundle\Form\Type\RegistrationFormType
      arguments: [ "%fos_user.model.user.class%"]
      tags:
          - { name: form.type, alias: sonata_user_registration }
  </code></pre>
  
  <p>config.yml:</p>
  
  <pre><code>fos_user:
      user_class:     Application\Sonata\UserBundle\Entity\User
      group:
          group_class:   Application\Sonata\UserBundle\Entity\Group
          group_manager: sonata.user.orm.group_manager
      service:
          user_manager: sonata.user.orm.user_manager 
      registration:
          form:
              type: sonata_user_registration 
  sonata_user:
      security_acl: true
      manager_type: orm 
  </code></pre>
  
  <p>and my DependencyInjection in //app/Application/Sonata/UserBundle/DependencyInjection</p>
  
  <pre><code>namespace Application\Sonata\UserBundle\DependencyInjection;
  
  use Symfony\Component\HttpKernel\DependencyInjection\Extension;
  use Symfony\Component\DependencyInjection\ContainerBuilder;
  use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
  use Symfony\Component\Config\FileLocator;
  
  class SonataUserExtension extends Extension
  {
      public function load(array $configs, ContainerBuilder $container)
      {
          $loader = new YamlFileLoader($container, new FileLocator(__DIR__.'/../Resources/config'));
          $loader-&gt;load('services.yml');
      }
  }
  </code></pre>