Parse error

function my_autoloader($class) {
    include 'classes/' . $class . '.php';
}

Fatal error: Class 'Security' not found in

function my_autoloader($class) {
    include 'classes/' . $class . '.php';
}

function my_autoloader($class) {
   require_once 'classes/' . $class . '.php'; 
}
spl_autoload_register('my_autoloader');

j'ai cette erreur avec mon fichier security.php

Fatal error: Class 'Security' not found in

...= new Security(); 

$erreur = "Ton compte a été supprimé";

Warning: Cannot modify header information - headers already sent by (output started at /home/cliquede/www/include/init.php:5) in /home/cliquede/www/page_accueil/connexion.php on line 18

<?php
class Connexion_class {
 
 private $pseudo;
 private $password;
 private $actif;
 
 private $bdd;
 
 public function __construct($pseudo, $password, $actif) {
  
  $password  = Security::hash($password);
   
  $this->pseudo = $pseudo;
  $this->password  = $password;
  $this->actif  = $actif;
  
  $this->bdd  = bdd();
 }
 
 private function ChampsVide() {
  return(empty($this->pseudo) || empty($this->password)) ? true : false;  
 }

 private function PseudoExist() {
  $sql = "SELECT *
    FROM  tb_adherent
    WHERE pseudo = :pseudo
    AND actif = 1";
  $requete = $this->bdd->prepare($sql);
  $requete->execute(array('pseudo' => $this->pseudo));
  $result = $requete->fetch();
  return ($result) ? $result['password'] : false;
 }

 private function Banni() {
  $sql = "SELECT *
    FROM  tb_adherent
    WHERE pseudo = :pseudo
    AND actif = 1";
  $requete = $this->bdd->prepare($sql);
  $requete->execute(array('pseudo' => $this->pseudo));
  $result = $requete->fetch();
  return($result['actif'] == 0) ? true : false;
 }
 
 private function Session() {
  $sql = "SELECT *
    FROM tb_gestion_admin
    INNER JOIN tb_adherent
    ON tb_adherent.id_adherent = tb_gestion_admin.rid_adherent
    WHERE pseudo = :pseudo
    AND actif = 1";
  $requete = $this->bdd->prepare($sql);
  $requete->execute(array('pseudo' => $this->pseudo));
  $result = $requete->fetch();
  $_SESSION['id_adherent'] = $result['id_adherent'];
  $_SESSION['prenom']    = $result['prenom'];
  $_SESSION['pseudo']    = $this->pseudo;
  $_SESSION['aucune_gestion']  = $result['aucune_gestion'];
  $_SESSION['membre']    = $result['membre'];
  $_SESSION['sortie']    = $result['sortie'];
  $_SESSION['cours']     = $result['cours'];
  $_SESSION['calendrier']   = $result['calendrier'];
 }
 
 public function VerifConnexion() {
  if($this->ChampsVide()) {
   $erreur = 'Veuillez remplir tous les champs';
   
  } else if($this->PseudoExist()) {
   if($this->password == $this->PseudoExist()) {
    if(!$this->Banni()) {
    
     $erreur = 'success';
     $this->Session();
     
    } else {
     $erreur = "Ton compte a été supprimé";
    }
   } else {
    $erreur = "Mauvais mot de passe...ou Mauvais login...Merci de recommencer.</br> Peut-être n'êtes vous pas membre de la Clique ? Dans ce cas désolé...";
   }
  } else {
   $erreur = "Ce compte n'existe pas";
  }
  return $erreur;
 }
}
?>

<?php include('connexion/config.php'); ?>
<?php $bdd = bdd(); ?>
<?php include('fonctions/fonction.php'); ?>

<?php
function my_autoloader($class) {
   require_once 'classes/' . $class . '.php'; 
}
spl_autoload_register('my_autoloader');
?>

if(session_id() == '') {
 session_start();
}