WebService security Unallowed RFC-XML Tag (SOAP_EINVALDOC)

Hi gurus,

I tried to setup webservice security on a NW2004 to send secure messages via https, webservice sercurity and soa. I managed it so far, that I can use https.

But when testing the connection (runtime workbench -> component monitoring -> integration engine -> webservice security available) I get an error

 Unallowed RFC-XML Tag (SOAP_EINVALDOC) 

.

Can anybody explain this error?

The logs (dev_rfcX) shows the following..

XRFC> INFO 15:35:57: SOAP SESSION Protocol CL_SOAP_SESSION_PROTOCOL       <
XRFC> ->IF_SOAP_PROTOCOL~PRE_PROCESS() Try to preprocess protocol SOAP    <
XRFC> Session Protocol ( Mode= ,Method= )                                 <
XRFC>                                                                     <
XRFC> INFO 15:35:57: SOAP SESSION Protocol CL_SOAP_SESSION_PROTOCOL       <
XRFC> ->IF_SOAP_PROTOCOL~PRE_PROCESS() SOAP Session Protocol              <
XRFC> preprocessed                                                        <
XRFC>                                                                     <
XRFC> INFO 15:35:57: SOAP Transport Binding CL_SOAP_HTTP_TPBND_ROOT       <
XRFC> ->IF_SOAP_TRANSPORT_BINDING~SEND() Try to send message ( DEST =     <
XRFC> WS_PROXY ,PATH = ,URL = ,SOAP Action = )                            <
XRFC>                                                                     <
XRFC> INFO 15:35:57: SOAP Transport Binding CL_SOAP_HTTP_TPBND_ROOT       <
XRFC> ->IF_SOAP_TRANSPORT_BINDING~SEND() Message sent                     <
XRFC>                                                                     <
XRFC> INFO 15:35:57: SOAP Transport binding CL_SOAP_HTTP_TPBND_ROOT       <
XRFC> ->IF_SOAP_TRANSPORT_BINDING~RECEIVE() Try to receive message        <
XRFC>                                                                     <
XRFC> ERROR 15:35:57: SOAP HTTP Binding CL_SOAP_HTTP_TPBND_ROOT->HANDLE   <
XRFC> _STATUS_CODE() Received return code 401 ( Unauthorized )            <
XRFC>                                                                     <
XRFC> ERROR 15:35:57: SOAP Message CL_SOAP_MESSAGE->IF_SOAP_MESSAGE       <
XRFC> _PART~INIT_FOR_DESERIALIZE() A SOAP Runtime Core Exception          <
XRFC> occurred in method XP_READ_TAG of class CL_SOAP_XP at position id   <
XRFC> 1 with internal error id 111 and error text Unallowed RFC-XML Tag   <
XRFC> (SOAP_EINVALDOC) (fault location is 1 ).                            <
XRFC>                                                                     <

I did not create any webservice security service the services are as out of the box. Do I have to create a service? If yes, could you please tell me how and what is nessesary?

Thank you for you help.

Best regards

Christian