Symfony2 - fosuserbundle - fosfacebookbundle Error : Array to string conversion

Question

I am trying to override the edit|profile form of fosuerbundle the process went well except in my case i am using fosfacebookbundle and we don't have facebook users password so every time i update it requires the password confirmation.Also I don't want to allow the users the right to modify their email,username at all i just want them to modify the other fields in my new form which contains stuffs like about me, interests. so i come with $builder->remove('username'); $builder->remove('email'); $builder->remove('current_password'); which hide those fields in the form now when i press update i have the following error :

An exception has been thrown during the rendering of a template ("Notice: Array to string    conversion in path to Symfony\vendor\symfony\symfony\src\Symfony\Component\Translation\Translator.php line 154") in "FOSUserBundle:Profile:show.html.twig".

500 Internal Server Error - Twig_Error_Runtime 1 linked Exception: ErrorException »

namespace path to\Form\Type ;
use Symfony\Component\Form\FormBuilderInterface;
use FOS\UserBundle\Form\Type\ProfileFormType as BaseType;

class Edit2FormType extends BaseType {

 public function buildForm(FormBuilderInterface $builder, array $options)
 {


    parent::buildForm($builder, $options);
      $builder->add('usermoreinfos',new moreaboutmyuserType(),array('label' => 'More Info'));

    $builder->remove('username');
    $builder->remove('email');
   $builder->remove('current_password');

 }




    public function getName()
   {
   return 'nameofmy_edit_profile';
  }
}

Hope you guys can help me find a solution and sorry for my bad english.Thank you.