Include a component in CakePHP 2 - model-view-controller

Question

I'm trying to working with Security component in a Controller of CakePHP 2.0 but I'm doing something wrong with it.
I've read in the documentation, but when I include the Security component in my Controller and I call the controller action register I get a blank page. If I comment the include public $components = array('Security'); it works again, where I'm wrong?
<?php
App::uses('CakeEmail', 'Network/Email');
class UsersController extends AppController {
public $components = array('Security');
public function register () {
if (!empty($this->data)) {
if ($this->data['User']['password'] == $this->data['User']['confirm_password']) {
$this->User->create();
$this->User->save($this->data);
$this->registrationEmail ($this->data['User']['email'], $this->data['User']['username']);
$this->redirect(array('controller'=>'users', 'action'=>'registration', 'success'));
}
}
}
private function registrationEmail ($account_email, $username) {
$email = new CakeEmail('myconfig');
$email->from(array('mailer#email.com' => 'MySite.com'));
$email->to($account_email);
$email->subject('Account activation / MySite.com');
$email->template('activation');
// $this->set('activation_code', Security->hash($account_email));
$email->viewVars(
array(
'activation_code' => $this->Security->hash($account_email),
'username' => $username
)
);
$email->send();
}
?>

Answer 1

How is the registration form rendered in your view file?
If you're using the Security Component, all form fields need to be generated using the FormHelper. In addition you can't fiddle with hidden values on the front end once they've been given a value by the FormHelper.