Workerman closes suddnly after send message - php

Question

I am using workerman PHP library to create WebSocket server.
require dirname(__DIR__) . '/vendor/autoload.php';
use Workerman\Worker;
// Create a Websocket server
$ws_worker = new Worker("websocket://0.0.0.0:8047");
// 4 processes
$ws_worker->count = 4;
// Emitted when new connection come
$ws_worker->onConnect = function($connection)
{
echo "New connection\n";
};
// Emitted when data received
$ws_worker->onMessage = function($connection, $data)
{
var_dump($data);
// Send hello $data
$connection->send('hello ' . $data);
};
// Emitted when connection closed
$ws_worker->onClose = function($connection)
{
echo "Connection closed\n";
};
// Run worker
Worker::runAll();
everything works fine. So I use this class to send message web socket server:
// https://github.com/Textalk/websocket-php
$client = new Client('ws://127.0.0.1:8047/');
$client->send('test !');
Sometimes output this error:
// Validate response.
if (!preg_match('#Sec-WebSocket-Accept:\s(.*)$#mUi', $response, $matches)) {
$address = $scheme . '://' . $host . $path_with_query;
throw new ConnectionException(
"Connection to '{$address}' failed: Server sent invalid upgrade response:\n"
. $response
);
}
If restart server it works again ... but every time after send connection is closes. I can't understand why connection closes.
PHP 7.2.0 (cli) (built: Nov 28 2017 23:48:49) ( ZTS MSVC15 (Visual C++ 2017) x64 )
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