Fatal error: Uncaught Error: Interface 'Ratchet\Session\Serialize\HandlerInterface' not found in /home/soh-works/www/websoket-sample/vendor/cboden/ratchet/src/Ratchet/Session/Serialize/PhpHandler.php:4
Stack trace:
#0 {main}
thrown in /home/soh-works/www/websoket-sample/vendor/cboden/ratchet/src/Ratchet/Session/Serialize/PhpHandler.php on line 4