Vichuploaderbundle：下载文件时的奇怪页面

I have to create a site for downloading packages. There is an account system (local or CAS authentication).

I use VichUploaderBundle to distribute my files. And I distribute them from a controller so that I can modify my database accordingly.

I have a user entity and a package entity. The user contains an ArrayCollection () of packages (manytomany).

If it downloads a package, then the downloaded package is added to its arrayCollection ().

The problem is this, when my user clicks on a package to download, the database is modified correctly, but the download does not start, and it is redirected to a weird page:

Image

I don't understand what is it ?

This is my code :

/** 
     * Lorsque l'on clique sur un package à télécharger ou sa notice : Téléchargement
     *
     * @Route("/{id}/{type}/file", name="user_paquet_fileDDL")
     */
    public function paquetFileAction(Paquet $paquet, $type)
    {

      //  $em = $this->getDoctrine()->getManager(); //Récupération du manager
        //$this->getDoctrine()->getManager()->getRepository('PagesBundle:User')->setDDL("loughin.bastien"); //On décrémente le nombre de DDL pour l'utilisateur en question
       // $user = $this->getUser();

        $downloadHandler = $this->get('vich_uploader.download_handler'); // On prépare le téléchargement

        if($type == "package") //Si l'utilisateur clique sur le lien du package, on lui donne le fichier package
        {

            $token = $this->get('security.token_storage')->getToken();

            $user = $token->getAttribute('user');
           // $user = $this->get('serializer')->deserialize($data, 'Site\PagesBundle\Entity\UserCas', 'json');


            $this->packageDDL($paquet,$user);

            return $downloadHandler->downloadObject($paquet, $fileField = 'paquetFile', Paquet::class, null);
        }

        else //Sinon c'est qu'il a cliqué sur le lien de la notice, alors on lui donne la notice associée au package
        {
            return $downloadHandler->downloadObject($paquet, $fileField = 'noticeFile', Paquet::class, null);
        }

    }

And when an User download the file, the called "packageDDL()" function :

public function packageDDL($paquet,$user)
        {
            $token = $this->get('security.token_storage')->getToken();
            $typeAuth = $token->getAttribute('typeAuth');

            dump($user);
            $em = $this->getDoctrine()->getManager(); //Récupération du manager
            $user->addPackage($paquet);
            $em->persist($user);
            $em->flush();

            if($typeAuth == 'cas')
            {
                $data = $this->get('serializer')->serialize($user, 'json');
                $token->setAttribute('user',$data) ;
            }
        }

Could anyone help me please ?