SocketException: An existing connection was forcibly closed by the remote host.

[Xihao Huang]

hi, I am having a issue with connect to CloudAMQP. That is the code and error

copy from the cloudamqp guideline. 

    void Start()
    {
private static readonly string _url = "amqp://guest:guest@localhost/%2f";
        // Create a ConnectionFactory and set the Uri to the CloudAMQP url
        // the connectionfactory is stateless and can safetly be a static resource in your app
        var factory = new ConnectionFactory
        {
            uri = new Uri(url)
        };
        // create a connection and open a channel, dispose them when done
   
        using var connection = factory.CreateConnection();
        using var channel = connection.CreateModel();
        // ensure that the queue exists before we publish to it
        var queueName = "queue1";
        bool durable = false;
        bool exclusive = false;
        bool autoDelete = true;

        channel.QueueDeclare(queueName, durable, exclusive, autoDelete, null);

        // read message from input
        var message = "";
        // the data put on the queue must be a byte array
        var data = Encoding.UTF8.GetBytes(message);
        // publish to the "default exchange", with the queue name as the routing key
        var exchangeName = "";
        var routingKey = queueName;
        channel.BasicPublish(exchangeName, routingKey, null, data);
 

    }

the issues is 

SocketException: An existing connection was forcibly closed by the remote host.

System.Net.Sockets.Socket.Receive (System.Byte[] buffer, System.Int32 offset, System.Int32 size, System.Net.Sockets.SocketFlags socketFlags) (at <aa976c2104104b7ca9e1785715722c9d>:0)
System.Net.Sockets.NetworkStream.Read (System.Byte[] buffer, System.Int32 offset, System.Int32 size) (at <aa976c2104104b7ca9e1785715722c9d>:0)
Rethrow as IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.

does any one know how to slove it?