Как исправить ошибку по PHP?

Fatal error: Call to protected GlobalClass::__construct() from context 'Modules' in N:\home\guru\www\lib\modules_class.php on line 27

public function __construct($db)
{
session_start();
$this->config = new Config($db);
$this->article = new Article($db);
27$this->section = new Section($db);
$this->user = new User($db);
$this->menu = new Menu($db);
$this->banner = new Banner($db);
$this->message = new Message();
$this->data = $this->secureData($_GET);
}

abstract class Modules {

protected $config;
protected $article;
protected $section;
protected $user;
protected $menu;
protected $banner;
protected $message;
protected $data;

abstract class Modules {

protected $config;
protected $article;
protected $section;
protected $user;
protected $menu;
protected $banner;
protected $message;
protected $data;