php - ratchet HttpServer class not found -

so made real-time chat on windows in php websockets , every thing worked when try run server on vps(debian) error

php fatal error:  class 'ratchet\http\httpserver' not found in /react-chat/bin/server.php on line 11 

so when @ server.php file :

<?php  require __dir__ . '/../vendor/autoload.php';  use chat\chat;  use ratchet\server\ioserver; use ratchet\http\httpserver; use ratchet\websocket\wsserver;  $server = ioserver::factory(new httpserver(new wsserver(new chat)), 2000);  $server->run(); 

every thing seems normal composer.json file

{     "require": {         "cboden/ratchet": "~0.3"     },     "autoload": {         "psr-4": {             "chat\\": "bin/src/"         }     } } 

the warning got when doing composer install following

but dont warning making error

php namespaces case sensitive, try http instead of http:

use ratchet\http\httpserver;