symfony 4.0 form_errors() doesn't work - php

Question

I'm using Symfony 4.0 framework I have a problem. I created form it works without a problem but I can't see form_errors() text, it's not working.
Where am I doing wrong in this code?
My controller:
$user = new Users();
$form = $this->createFormBuilder($user)
->add('firstName', TextType::class, array('label'=> 'Name','error_bubbling' => false))
->add('lastName',TextType::class, array('label'=> 'Lastname','error_bubbling' => false))
->add('Email', EmailType::class, array('label' => 'Email','error_bubbling' => false))
->add('Password', RepeatedType::class, array(
'type' => PasswordType::class,
'error_bubbling' => false,
'invalid_message' => 'The password fields must match.',
'options' => array('attr' => array('class' => 'password-field')),
'first_options' => array('label' => 'Password','error_bubbling' => true),
'second_options' => array('label' => 'Repeat Password'),
))
->add('Save', SubmitType::class, array('label' => 'Register'))
->getForm();
$data['form'] = $form->createView();
$form->handleRequest($request);
$errors = $validator->validate($user);
if($errors->count() > 0){
$data['errors'] = $errors;
return $this->output('user/register',$data);
}
I created form cannot get twig render. Can't see errors text
..html.twig:
{{ form_start(form) }}
{{ form_row(form) }}
{{ form_end(form) }}