No event handler found for received PDU DeliverSm

[owlboo98]

Hello Team,
I am using library version 2.9.35 and found an error on receive the delivery report from our partner gateway.
As checking from DEBUG log, I found the below information

2025-02-21 05:23:52,386 [198] WARN X-Transceiver-1 - No event handler found for received PDU: DeliverSm, Sequence: 1772599, SourceAddr: xxxx, DestAddr: xxxx
2025-02-21 05:23:52,386 [198] DEBUG X-Transceiver-1 - Send PDU: DeliverSmResp, Status: ESME_RINVCMDID, Sequence: 1772599

But checking from our source, we found the "DetachEvents" function and that will only be fired once I manually call Unbind via API and the client will be disposed after that.

Code: Select all

private void _client_evUnBind(object sender, Inetlab.SMPP.PDU.UnBind data)
{
    //throw new NotImplementedException();

    SmppClient client = (SmppClient)sender;

    Console.WriteLine($"Unbind the session {client.RemoteEndPoint}/{client.SystemID}");

    DetachEvents(client);
}
private void AttachEvents(SmppClient client)
{
    client.evDisconnected += _client_evDisconnected;
    client.evUnBind += _client_evUnBind;
    client.evPduReceiving += _client_evPduReceiving;
    client.evPduSending += _client_evPduSending;
    client.evDeliverSm += _client_evDeliverSm;
}

private void DetachEvents(SmppClient client)
{

    client.evDisconnected -= _client_evDisconnected;
    client.evUnBind -= _client_evUnBind;
    client.evPduReceiving -= _client_evPduReceiving;
    client.evPduSending -= _client_evPduSending;
    client.evDeliverSm -= _client_evDeliverSm;
}

In addition, at the first time of initialization the connectivity, all things are going well but after a month the issue was happened.

Kindly give me some helps.