Uhm...

$request->file('customFile')

why did you not try this?

Thank's for u'r reply.

I have tried it too but empty too. I just forgot to put it in my exemple here. Anyway, i think that

$request->file('customFile')

is the same than

Input::file('customFile')

Well that is indeed weird then. Did you try to add

use Symfony\Component\HttpFoundation\File\UploadedFile;

into controller?

Yes. I found this tip during my research on the net. But unfortunately it does not change anything :(

Can you post the controller class definition and constructor? Maybe there is something wrong there

Also: what does $request->hasFile() return?

Ok. This is the whole Controller. Upload method is at the very bottom.

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

use App\Custom\GoogleMap;
use App\Parlors;
use App\ParlorContacts;
use App\ParlorSchedules;
use App\ParlorPictures;
use App\ParlorTexts;
use App\Services;
use App\RatpStops;
use App\Massages;
use Illuminate\Support\Facades\Input;
use Symfony\Component\HttpFoundation\File\UploadedFile;

class ParlorsController extends Controller
{
    /**
     * Liste des salons enregistrés
     */
    public function index() {
        $parlors = \Auth::user()->parlors()->get();

        return view('admin.parlors.home', [
            'parlors' => $parlors
        ]);
    }

    /**
     * Première étape de création d'un salon
     * @param Request $request
     */
    public function create(Request $request) {

        //Si c'est du get on vide la session et on affiche le formulaire
        if($request->getMethod() == 'GET') {
            session()->forget('parlorCreate');
            return view('admin.parlors.create');
        }

        //On génère la map via Google
        $img = GoogleMap::getStaticMapURL($request->get('latitude'), $request->get('longitude'));
        session( ['parlorCreate' => array_merge($request->all(), ['img' => $img])] );

        return response()->json( session('parlorCreate') );
    }

    /**
     * Deuxième étape de création d'un salon
     * @param $parlorId
     * @param Request $request
     */
    public function createStep2($parlorId, Request $request) {

        //Si on est en GET, on affiche le formulaire
        if($request->getMethod() == 'GET')
            return view('admin.parlors.createStep2', ['parlorID' => $parlorId]);

        //ON enregistre le téléphone
        ParlorContacts::add($parlorId, 'PHONE', $request->get('inputParlorPhone'));
        //On enregistre les plages horaires
        ParlorSchedules::add($request, $parlorId);

        return redirect('/admin/parlors/'.$parlorId);
    }

    /**
     * On va créer le salon en base depuis la session
     */
    public function save() {

        $parlor = Parlors::add();

        //On cherche les stations les plus proches et on les affecte si y'en à (que pour Paris/RATP)
        $stops = RatpStops::getStationsAround($parlor->location, 200);
        $parlor->stations()->attach($stops);

        return redirect('/admin/parlors/create/'.$parlor->id);
    }

    /**
     * Details d'un salon
     * @param $parlorId
     */
    public function details($parlorId) {

        $parlor = Parlors::find($parlorId);

        return view('admin/parlors/details', ['parlor' => $parlor]);
    }

    /**
     * Mise à jour des jours et horaires d'ouverture
     * @param $parlorId
     * @param Request $request
     * @return \Illuminate\Http\RedirectResponse|\Illuminate\Routing\Redirector
     */
    public function editSchedule($parlorId, Request $request) {

        ParlorSchedules::add($request, $parlorId);

        return redirect('/admin/parlors/'.$parlorId);
    }

    /**
     * Mise à jour du text
     * @param $parlorId
     * @param Request $request
     * @return \Illuminate\Http\RedirectResponse|\Illuminate\Routing\Redirector
     */
    public function editText($parlorId, Request $request) {

        ParlorTexts::add($parlorId, $request->get('text'));

        return redirect('/admin/parlors/'.$parlorId);
    }

    /**
     * Mise à jour des services
     * @param $parlorId
     * @param Request $request
     */
    public function editServices($parlorId, Request $request) {

        Services::add($parlorId, $request->all());

        return redirect('/admin/parlors/'.$parlorId);
    }

    public function editMassages($parlorId, Request $request) {
        Massages::add($parlorId, $request->all());

        return redirect('/admin/parlors/'.$parlorId);
    }

    /**
     * Modification d'un contact
     * @param $parlorId
     * @param $contactId
     * @param Request $request
     */
    public function editContact($parlorId, $contactId, Request $request) {

        ParlorContacts::edit($contactId, $request->get('value'));

        return redirect('/admin/parlors/'.$parlorId);
    }

    /**
     * Ajout d'un contact
     * @param $parlorId
     * @param Request $request
     * @return \Illuminate\Http\RedirectResponse|\Illuminate\Routing\Redirector
     */
    public function addContact($parlorId, Request $request) {

        ParlorContacts::add($parlorId, $request->get('type'), $request->get('value'),false);

        return redirect('/admin/parlors/'.$parlorId);
    }

    /**
     * Suppression d'un contact
     * @param $parlorId
     * @param $contactId
     * @return \Illuminate\Http\RedirectResponse|\Illuminate\Routing\Redirector
     */
    public function deleteContact($parlorId, $contactId) {

        ParlorContacts::remove($contactId);

        return redirect('/admin/parlors/'.$parlorId);
    }

    /**
     * Upload d'une image pour le salon
     * @param $parlorId
     * @param Request $request
     * @return \Illuminate\Http\JsonResponse
     */
    public function uploadPicture($parlorId, Request $request) {

        return response()->json([
            '$_FILES' => $_FILES,
            'RequestAll' => $request->all(),
            'isValid' => $request->file('customFile')->isValid(),
            'Direct' => $request->customFile,
            'test' => Input::file('customFile'),
            'file' => $request->file('customFile')
        ]);
    }
}

Maaan I tried your code, this is interesting. Try this. Remove all code in uploadPicture and only return this

return $request->file('customFile')

Then, I do not know if json has some restrictions or what is going on why it shows empty value, but try also this

return response()->json([
   'file' => $request->file('customFile')->getClientOriginalName()
]);

it works! :)