Fatal error: Uncaught RuntimeException: Failed to listen on "tcp://127.0.0.1:9001": Address already in use in /var/www/html/api/app_old/chat/socket/vendor/react/socket/src/TcpServer.php:164 Stack trace: #0 /var/www/html/api/app_old/chat/socket/vendor/react/socket/src/Server.php(36): React\Socket\TcpServer->__construct('tcp://127.0.0.1...', Object(React\EventLoop\StreamSelectLoop), Array) #1 /var/www/html/api/app_old/chat/socket/vendor/ratchet/rfc6455/tests/ab/startServer.php(10): React\Socket\Server->__construct('127.0.0.1:9001', Object(React\EventLoop\StreamSelectLoop)) #2 {main} thrown in /var/www/html/api/app_old/chat/socket/vendor/react/socket/src/TcpServer.php on line 164