Error When Starting Up the SAP Connector - "service '?' unknown"

Description

When trying to start the SAP Connector See Loftware Connector., the following error is observed in the "NLINK RfcListener CoNNector2 Trace" log file;

21-Feb-14 12:54:11: Registration failed for destination 'LOFTWARE1', GwHost '216.138.94.180', SAP System ID '', External System 'Loftware Listener' (13). Error details
Code '1': Group A logical organization of resources. Resources are not failed from one cluster member to another, groups are. This allows the administrator to place dependent resources into one unit, which guarantees that the same cluster member always owns a resource and all its dependencies. '4': Key 'RFC_COMMUNICATION_FAILURE': Message '
ERROR service '?' unknown
TIME Fri Feb 21 12:54:11 201
RELEASE 711
COMPONENT NI (network interface)
VERSION 39
RC -3
DETAIL NiErrSet
COUNTER 2
': abapMsgClass '': abapMsgType '': abapMsgNumber '216923562': V1 '': V2 '': V3 '': V4 ''

Cause

This is caused by an erroneous "GWSERV" value in the SAPNWRFC.INI file

Example

/*===================================================================*/
/* Type R: Register a RFC server program at a SAP gateway */
/* or connect to an already registered RFC server program */
/*===================================================================*/

DEST=LOFTWARE1
TYPE=R
PROGRAM_ID=loftware_lps_rfc_listener_1 
GWHOST=216.138.94.180
GWSERV=badservername

Solution

Get the correct SAP system identification,  put that as the "GWSERV" value in the SAPNWRFC.INI file, then restart the SAP Connector service.