MQTTnet.Exceptions.MqttProtocolViolationException: Received packet 'SubAck: [PacketIdentifier=3491] [ReturnCodes=SuccessMaximumQoS2] [ReasonCode=]' at an unexpected time.

[zhujinhu21]

Describe the bug

when i subscribeasync topic ,it happend error. already connected mqttserver

Which project is your bug related to?

• Client

To Reproduce

Steps to reproduce the behavior:

1. MQTTnet 3.0.15.

await _mqttNetClient.SubscribeAsync(subscribeTopic, MqttQualityOfServiceLevel.ExactlyOnce); 

happend error

Additional context / logging

14:03:46.065 2 N - MQTTnet.Exceptions.MqttProtocolViolationException: Received packet 'SubAck: [PacketIdentifier=3491] [ReturnCodes=SuccessMaximumQoS2] [ReasonCode=]' at an unexpected time.
at MQTTnet.Client.MqttClient.TryProcessReceivedPacketAsync(MqttBasePacket packet, CancellationToken cancellationToken)
at MQTTnet.PacketDispatcher.MqttPacketAwaiter1.WaitOneAsync(TimeSpan timeout) at MQTTnet.Client.MqttClient.SendAndReceiveAsync[TResponsePacket](MqttBasePacket requestPacket, CancellationToken cancellationToken) at MQTTnet.PacketDispatcher.MqttPacketAwaiter1.WaitOneAsync(TimeSpan timeout)
at MQTTnet.PacketDispatcher.MqttPacketAwaiter1.WaitOneAsync(TimeSpan timeout) at MQTTnet.Client.MqttClient.SendAndReceiveAsync[TResponsePacket](MqttBasePacket requestPacket, CancellationToken cancellationToken) at MQTTnet.Client.MqttClient.SubscribeAsync(MqttClientSubscribeOptions options, CancellationToken cancellationToken) at MQTTnet.Client.MqttClient.SubscribeAsync(MqttClientSubscribeOptions options, CancellationToken cancellationToken) at MQTTnet.Client.MqttClient.SendAndReceiveAsync[TResponsePacket](MqttBasePacket requestPacket, CancellationToken cancellationToken) at MQTTnet.Client.MqttClient.SubscribeAsync(MqttClientSubscribeOptions options, CancellationToken cancellationToken) at MQTTnet.PacketDispatcher.MqttPacketAwaiter1.WaitOneAsync(TimeSpan timeout)
at MQTTnet.Client.MqttClient.SendAndReceiveAsync[TResponsePacket](MqttBasePacket requestPacket, CancellationToken cancellationToken)
at MQTTnet.PacketDispatcher.MqttPacketAwaiter`1.WaitOneAsync(TimeSpan timeout)
at MQTTnet.Client.MqttClient.SubscribeAsync(MqttClientSubscribeOptions options, CancellationToken cancellationToken)
at MQTTnet.Client.MqttClient.SendAndReceiveAsync[TResponsePacket](MqttBasePacket requestPacket, CancellationToken cancellationToken)
at MQTTnet.Client.MqttClient.SendAndReceiveAsync[TResponsePacket](MqttBasePacket requestPacket, CancellationToken cancellationToken)
at MQTTnet.Client.MqttClient.SubscribeAsync(MqttClientSubscribeOptions options, CancellationToken cancellationToken)
at MQTTnet.Client.MqttClient.SubscribeAsync(MqttClientSubscribeOptions options, CancellationToken cancellationToken)

[chkr1011]

Please try with the latest version of the library and reopen this ticket if the error persists.