Hi everyone, I created the workflow for afternoon demo and it's works fine in past 2 months.

This morning, I got workflow error when I try to get SN / connect to K2, may I ask your advice?

 Version: k2 black pearl 4.6.4

 Development Tool: MS VS 2012

-------- Error Message.-----------

System.Net.Sockets.SocketException: A request to send or receive data was disallowed because the socket is not connected and (when sending on a datagram socket using a sendto call) no address was supplied;   at System.Net.Sockets.Socket.Shutdown(SocketShutdown how);   at SourceCode.Hosting.Client.BaseAPI.SocketBaseAPIConnection.OnClose();   at SourceCode.Hosting.Client.BaseAPI.BaseAPIConnection.Close();   at SourceCode.Hosting.Client.BaseAPI.BaseAPIConnectionBroker.OnClose();   at SourceCode.Hosting.Client.BaseAPI.BaseAPIConnection.Close();   at XXX.GetSN(String Host, UInt32 Port, String ProcessName, String K2Admin, String K2AdminPassword, String RequestID);   at XXX.frmNewCase.WorkflowProceed(String EmailTemplate, Int32 Scheme, String WorkflowPortfolio, Int32 intCaseID, String Action);   at XXX.frmCaseDetails.SubmitApproval()

-------- Please reference following code blocks for your reference.-----------

//Caller

string _SN = GetSN(Host, Port, strWorkflowName, K2Admin, K2Password, WorkflowPortfolio);

//Helper Class

 /// <summary>
        /// Get SN
        /// </summary>
        public static string GetSN(string Host, uint Port, string ProcessName, string K2Admin, string K2AdminPassword, string RequestID)
        {

            string ret = "";


            SourceCode.Hosting.Client.BaseAPI.SCConnectionStringBuilder connectionString = new SourceCode.Hosting.Client.BaseAPI.SCConnectionStringBuilder();

            connectionString.Authenticate = true;

            connectionString.Host = Host;

            connectionString.Integrated = true;

            connectionString.IsPrimaryLogin = true;

            connectionString.Port = Port;

            connectionString.UserID = K2Admin;

            connectionString.Password = K2AdminPassword;

            WorkflowManagementServer WorkflowServer = new WorkflowManagementServer();

            try
            {

                WorkflowServer.CreateConnection();

                WorkflowServer.Connection.Open(connectionString.ToString());


                WorklistItems items = WorkflowServer.GetWorklistItems("", ProcessName, "", "", RequestID, "", "");


                if (items.Count > 0)
                {
                    ret = itemse0].ProcInstID.ToString() + "_" + items_0].ActInstDestID.ToString();
                    return ret;
                }

            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                WorkflowServer.Connection.Close();
            }

            return ret;
        }

Thank you very much for attention.