Session enabled RFC Web Service Fails & WSDL has enablesession=false

Question

Please help  Thanks in Advance
A stateful Webservice with 2 RFCs, consumed by a .NET application fails and the cause seems to be because of statelessness.
The call to 1st RFC succeeds and the call to the 2nd RFC fails with the below error message:
An exception with the type CX_SY_REF_IS_INITIAL occurred, but was neither handled locally,
nor declared in a RAISING clause.Dereferencing of the NULL reference"
Question:
1- Even though the "Session-Oriented Communication" is checked, the WSDL has EnableSession as false. Is there any special step to make it true?
2- Even though the SOA Manager says that the Session is enabled and SessionMode is Http Cookie, the HTTPFiddler doesn't show any cookie in the .NET side.
3- Are Web Service enabled HRXSS RFCs capable of performing Session Oriented Communication?
Eg. Can the RFCs HrxssPerInitPernr and HrxssPerReadP0002Us be called in a sequence?
service ws = new service();
            ws.Credentials = new System.Net.NetworkCredential("abcd", "abcd");
            System.Net.CookieContainer cookie1 = new System.Net.CookieContainer();
            ws.CookieContainer = cookie1;
            //BELOW CALL SUCCEEDS
           HrxssPerInitPernrResponse response = ws.HrxssPerInitPernr(new HrxssPerInitPernr()
{ Infty = "0002", Pernr = "52222068", Userdate="2009-01-01" });
            HrxssPerReadP0002Us read = new HrxssPerReadP0002Us() { Infty = "0002"  };
          // BELOW CALL FAILS
            HrxssPerReadP0002UsResponse readResponse = ws. HrxssPerReadP0002Us (read);
            HcmtBspPaUsR0002 [] records = readResponse.Records;
EXCEPTION
System.Web.Services.Protocols.SoapException was unhandled
  Message="CX_SY_REF_IS_INITIAL:Exception CX_SOAP_ROOT occurred (program: CL_SOAP_RUNTIME_ROOTCP,
include:CL_SOAP_RUNTIME_ROOT CM004, line: 110)
An exception with the type CX_SY_REF_IS_INITIAL occurred,
but was neither handled locally, nor declared in a RAISING clause.Dereferencing of the NULL reference"
  Source="System.Web.Services"
  Actor=""  Lang="en"  Node=""  Role=""   StackTrace:
       at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke  at HrxssPerReadP0002Us
Edited by: Tony TB on Jul 2, 2009 9:56 AM

Answer 1

to get this working you need to enable some services in transaction SICF
to know a complete list of all services to be enabled check oss note number 517484
particularly these nodes should be active
/default_host/sap/bc/soap/wsdl and
/default_host/sap/bc/soap/wsdl11
(to get the error thrown by the server instead of page cannot be found, in your browser go to tools->internet options->advanced and uncheck the check box "show friendly error messages" and run the wsdl button again)
Regards
Raja