ReflectionException in Container.php line 749

I've just installed a Laravel based Application, which seems to work for some of its pages, however many others throw an error and make access to settings or profiles completely impossible. I've seen there are quite a few solutions available online, such as checking writing permissions, etc. however nothing seems to currently work for me, therefore some expert help would be definitely appreciated.

Here my error:

    ReflectionException in Container.php line 749:
    Class App\Http\Controllers\UserController does not exist
    in Container.php line 749
    at ReflectionClass->__construct('App\Http\Controllers\UserController') in Container.php line 749
    at Container->build('App\Http\Controllers\UserController', array()) in Container.php line 644
    at Container->make('App\Http\Controllers\UserController', array()) in Application.php line 709
    at Application->make('App\Http\Controllers\UserController') in Route.php line 203
    at Route->getController() in Route.php line 316
    at Route->controllerMiddleware() in Route.php line 278
    at Route->gatherMiddleware() in Router.php line 666
    at Router->gatherRouteMiddleware(object(Route)) in Router.php line 646
    at Router->runRouteWithinStack(object(Route), object(Request)) in Router.php line 629
    at Router->dispatchToRoute(object(Request)) in Router.php line 607
    at Router->dispatch(object(Request)) in Kernel.php line 268
    at Kernel->Illuminate\Foundation\Http\{closure}(object(Request)) in Pipeline.php line 53
    at Pipeline->Illuminate\Routing\{closure}(object(Request)) in CheckForMaintenanceMode.php line 46
    at CheckForMaintenanceMode->handle(object(Request), object(Closure)) in Pipeline.php line 137
    at Pipeline->Illuminate\Pipeline\{closure}(object(Request)) in Pipeline.php line 33
    at Pipeline->Illuminate\Routing\{closure}(object(Request)) in Pipeline.php line 104
    at Pipeline->then(object(Closure)) in Kernel.php line 150
    at Kernel->sendRequestThroughRouter(object(Request)) in Kernel.php line 117
    at Kernel->handle(object(Request)) in index.php line 53

Here is the UserController:

    <?php

    namespace App\Http\Controllers;

    use Illuminate\Http\Request;
    use Illuminate\Support\Facades\Auth;
    use App\User;
    use App\Contact;
    use Storage;
    use File;

    class Usercontroller extends Controller
    {
        //

        private $rules = [

                'name' => ['required' , 'min:5'],
                'email' => ['required' , 'email'],

                'photo'=>   ['mimes:jpg,jpeg,png,gif,bmp']


            ];
            private $upload_dir = 'public/uploads' ;

            public function __construct()
            {
                $this->middleware('auth');
                $this->upload_dir = base_path() .'/'. $this->upload_dir;

            }


        private function getRequest(Request $request)
        {

            $data = $request->all();
            if($request->hasFile('photo'))
            {

            $photo       = $request->file('photo');
            $filename    ="laravel-contact-".time()."-".uniqid()."-".$photo->getClientOriginalName();
            Storage::put($filename, File::get($photo->getRealPath()));

            $data = $request->all();
            $data ['photo'] = $filename;

            }

            return $data;
        }


            public function profile()
            {
            //return view('user.profile', ['user' => User::findOrFail($id)]);
            $id = Auth::id();

            $user = User::findOrFail($id);
            //$this->authorize('modify',$contact);
            return view('user.profile',compact('user'));    
            }

        public function show($id)
            {
            //return view('user.profile', ['user' => User::findOrFail($id)]);

            $user = Contact::findOrFail($id);
            //$this->authorize('modify',$contact);
            return view('user.index',compact('user'));  
            }


        public function update(Request $request)
        {

            $this->validate($request,$this->rules);
            $data = $this->getRequest($request);

            $id = Auth::id();

            $user = User::findOrFail($id);
            $user->update($data);
            $oldPhoto = $user->photo;

            if ($oldPhoto !== $user->photo){
                $this->removePhoto($oldPhoto);
            }
            return redirect('profile/settings')->with('message','profile updated');

        }





     public function password()
        {
            return view('user.password');
        }

    public function resetPassword(Request $request)
    {
            $this->validate($request, [
                'password' => 'required|confirmed|min:6',
            ]);

            $user = $request->user();
            $user->password = bcrypt($request->get('password'));
            $user->save();
            $id = Auth::id();

            $user = User::findOrFail($id);

            return view('user.index',compact('user'));  

    }

        public function removePhoto($photo)
        {

            if (! empty($photo))
            {
            $path = storage_path('app/public/images/' . $photo);

             if (File::exists($path)) {
                File::Delete($path);
            }
        }





        }



    }

Here my .env file (which I checked for not containing any spaces):

    APP_ENV=local
    APP_KEY=base64:hcoymkbh8WxkAuetCUOPI3TJ30DrjVzkvNBOigjwopw=
    APP_DEBUG=true
    APP_LOG_LEVEL=debug
    APP_URL=http://myurl.com

    DB_CONNECTION=mysql
    DB_HOST=localhost
    DB_PORT=3306
    DB_DATABASE=xxxx
    DB_USERNAME=xxxx
    DB_PASSWORD=xxxx

    BROADCAST_DRIVER=log
    CACHE_DRIVER=file
    SESSION_DRIVER=file
    QUEUE_DRIVER=sync

    REDIS_HOST=127.0.0.1
    REDIS_PASSWORD=null
    REDIS_PORT=6379

    MAIL_DRIVER=smtp
    MAIL_HOST=mailtrap.io
    MAIL_PORT=2525
    MAIL_USERNAME=null
    MAIL_PASSWORD=null
    MAIL_ENCRYPTION=null

    PUSHER_APP_ID=
    PUSHER_KEY=
    PUSHER_SECRET=

and last but not least, my nginx configuration file for this project:

    server {
        listen 80;
        server_name myurl.com;
        root /var/www/html/public;

        add_header X-Frame-Options "SAMEORIGIN";
        add_header X-XSS-Protection "1; mode=block";
        add_header X-Content-Type-Options "nosniff";

        index index.html index.htm index.php;

        charset utf-8;

        location / {
            try_files $uri $uri/ /index.php?$query_string;
        }

        location = /favicon.ico { access_log off; log_not_found off; }
        location = /robots.txt  { access_log off; log_not_found off; }

        error_page 404 /index.php;

        location ~ \.php$ {
            fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;
            fastcgi_index index.php;
            fastcgi_param SCRIPT_FILENAME $realpath_root$fastcgi_script_name;
            include fastcgi_params;
        }

        location ~ /\.(?!well-known).* {
            deny all;
        }
    }

Some expert insight would be truly appreciated, thank you very much

via Chebli Mohamed