Fatal error: Uncaught Error: Interface "Ratchet\Session\Serialize\HandlerInterface" not found in /var/www/html/mun/vendor/cboden/ratchet/src/Ratchet/Session/Serialize/PhpBinaryHandler.php:4 Stack trace: #0 {main} thrown in /var/www/html/mun/vendor/cboden/ratchet/src/Ratchet/Session/Serialize/PhpBinaryHandler.php on line 4