Fatal error: Uncaught Error: Call to undefined method Loader

[lucavalentino]

Sto creando un plugin per Wordpress, ma credo sia un errore del php.
Non riesco ad accedere ad alcune funzioni di altre class e ricevo tale errore:
Fatal error: Uncaught Error: Call to undefined method Loader::get_utente()
file controller

class Controller{
public $load; public $model; 
function __construct() {  
global $wpdb;  
include_once(plugin_dir_path(dirname(__FILE__)).'loaders/loaders.php');
include_once(plugin_dir_path(dirname(__FILE__)).'models/models_m.php'); 
$this->$model = new Model_M();  $this->$load = new Loader();}
public function index(){  $dati=$this->show();...... } 
public function show(){ $this->$model->get_utente();.....} 

file model

class Model_M{
function __construct() {} 
function get_utente(){ 
$sql='SELECT p.* FROM tblprova p ORDER BY utente';  $result=$GLOBALS['wpdb']->get_results($sql,OBJECT_K);   return $result; }
}