The form's view data is expected to be an instance of class … but is a(n) string

Question

I am currently receiving the following error:

\"The form\'s view data is expected to be an instance of class Symfony\\Component\\HttpFoundation\\File

Answer 1

Here is the answer:

{
      $builder
          ->add('file', FileType::class, array('data_class' => null))
          ->add('coverFile', FileType::class, array('data_class' => null))
          ->add('coverFile', FileType::class, array('data_class' => null,'required' => false))
          ->add('songName', TextType::class)
          ->add('songAuthor', TextType::class);
  }