System.NullReferenceException in OnConnectedAsync

[behroozbc]

hi
I get this error lot in my logs in MQTT.Server
my asp.net core version 6 and MQTTnet.AspNetCore 3.1.0
Why this happend

{
    "_id": ObjectId("61c83d465c1391f77fb1be08"),
    "Timestamp": ISODate("2021-12-26T10:00:37.924Z"),
    "Level": "Error",
    "MessageTemplate": "Unhandled exception while processing {ConnectionId}.",
    "RenderedMessage": "Unhandled exception while processing \"0HME648GR7STD\".",
    "Exception": "System.NullReferenceException: Object reference not set to an instance of an object.\n   at MQTTnet.Server.Internal.MqttClientSessionsManager.HandleClientConnectionAsync(IMqttChannelAdapter channelAdapter, CancellationToken cancellationToken)\n   at MQTTnet.AspNetCore.MqttConnectionHandler.OnConnectedAsync(ConnectionContext connection)\n   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure.KestrelConnection`1.ExecuteAsync()",
    "Properties": {
        "ConnectionId": "0HME648GR7STD",
        "SourceContext": "Microsoft.AspNetCore.Server.Kestrel"
    },
    "UtcTimestamp": "2021-12-26 10:00:37Z"
}

[behroozbc]

I find it's about this issue
#1284