Stage Initialized has no additional middlewares registered

[priore]

Hello,
in what case is the error in question generated?
I cannot understand why this error is generated and does not send messages.

            private RawRabbit.Instantiation.Disposable.BusClient client;


            try
            {
               var config = new RawRabbitConfiguration()
                {
                    Username = username,
                    Password = password,
                    VirtualHost = "/",
                    Hostnames = new List<string>() { hostname },
                    AutoCloseConnection = false,
                    //Ssl = new SslOption() {  Enabled = true },
                    Port = port,
                    Exchange = new GeneralExchangeConfiguration
                    {
                        AutoDelete = false,
                        Durable = true,
                        Type = RawRabbit.Configuration.Exchange.ExchangeType.Direct
                    },
                    Queue = new GeneralQueueConfiguration
                    {
                        Exclusive = false,
                        AutoDelete = false,
                        Durable = true
                    }
                };

                var options = new RawRabbitOptions() { ClientConfiguration = config };
                client = RawRabbitFactory.CreateSingleton(options);

                client.SubscribeAsync<MessageModel>(async msg =>
                {
                    return await Task.Run(() => MessageReceived(msg));
                },
                ctx => ctx.UseSubscribeConfiguration(
                    cfg => cfg.FromDeclaredQueue(
                        queue => queue.WithName(queueName))))
                        .GetAwaiter();
            }
            catch (Exception ex)
            {
                OnError?.Invoke(this, ex);
            }

please help me.