Photo not being uploaded after ajax request

Question

The question was asked before but I have made the things from the other question and I still can not make it work. After clicking button to submit the form's data I get error: Call to a member function guessExtension() on string (500 Internal Server Error). This is took from the response in the network tab. I am sure there is no string, because I have checked and it gives me the data in the form of array with key value pairs(checked it with ordinary request which redirects and dumped the $file variable). This is the code of my controller:

/**
 * @Route("/upload", name="uploadpic")
 * @param Request $request
 * @return JsonResponse|\Symfony\Component\HttpFoundation\Response
 */
public function uploadAction(Request $request){
    if(!$request->isXmlHttpRequest()){
        return new JsonResponse(
            array(
                'message' => 'Error',
                'status' => 'Not received'
            ), 400);
    }

    $user = $this->get('security.token_storage')->getToken()->getUser();
    $formed = $this->createForm(UserPicType::class, $user);//dadoh v barzinata User::class i gramna s: class does not implement “Symfony\Component\Form\FormTypeInterface”
    $formed->handleRequest($request);
    if(isset($request->request)) {


        $file = $request->files->get('user_pic_type')['userPic'];

        $file = $user->getUserPic();
        $fileName = $this->generateUniqueFileName() . '.' . $file->guessExtension();


        $file->move(
            $this->getParameter('users_directory'),
            $fileName
        );

        $user->setUserPic($fileName);


        $em = $this->getDoctrine()->getManager();
        $em->persist($user);
        $em->flush();



        return $this->redirectToRoute('profile');

    }
    return $this->render('default/index.html.twig',
        ['formed' => $formed->createView(),
            'posts' => null]);


}

private function generateUniqueFileName()
{
    return md5(uniqid());
}

Here is my ajax request:

$("#submit_pic").on('click', function(event){
    event.preventDefault();
    event.stopPropagation();
    $.ajax({
        type: "post",
        url: "/upload",
        data: new FormData($("#pic_data")[0]),
        processData: false,
        contentType: false,
        success: function () {
            console.log('success');
        },
        error: function (response) {
            console.log(response);
        }
    });
});

My template:

<form method="POST" enctype="multipart/form-data" action="{{ path('uploadpic') }}">
      <p>
          <input type="file" id="pic_data" name="user_pic_type[userPic]" required>
      </p>
          <button type="submit" id="submit_pic" name="" class="btn btn-success btn-sm">
                Change
          </button>
 </form>

When I use dump($file):

DefaultController.php on line 62:
UploadedFile {#38 ▼
  -test: false
  -originalName: "filedd.jpg"
  -mimeType: "image/jpeg"
  -size: 7256
  -error: 0
  path: "C:\xampp\tmp"
  filename: "phpB394.tmp"
  basename: "phpB394.tmp"
  pathname: "C:\xampp\tmp\phpB394.tmp"
  extension: "tmp"
  realPath: "C:\xampp\tmp\phpB394.tmp"
  aTime: 2019-01-02 02:08:13
  mTime: 2019-01-02 02:08:13
  cTime: 2019-01-02 02:08:13
  inode: 0
  size: 7256
  perms: 0100666
  owner: 0
  group: 0
  type: "file"
  writable: true
  readable: true
  executable: false
  file: true
  dir: false
  link: false
  linkTarget: "C:\xampp\tmp\phpB394.tmp"
}

So I do get file in the database and my folder when I use ordinary request which refreshes/redirects me, but when I try ajax it spits the error. Any idea why ?