$form['#validate'] must be checked

In my setup, just after installing the module, I get a fatal error (Unsopported operand types).
This is because in email_registration_form_alter(), when you sum up the #validate form field, you don't check if the current #validate is null or not (In my case it is). I simpy use a cast to (array), that way:

      $form['#validate'] = array('email_registration_user_login_validate' => array()) + (array)$form['#validate'];