BW Connection fails

1 Summary
2 Error

Summary

Your connection to an SAP System fails.

Error

Error: Authentication in SAP failed.

Connect to SAP gateway failed
SNCERR_UNKNOWN_MECH

Verbindung zu BW3 fehlgeschlagen: RfcOpenEx failed(RFC_ERROR_COMMUNICATION) SAP_CMINIT3 : rc=20 > Connect to SAP gateway failed 
Connect_PM GWHOST=example.sap.org, GWSERV=sapgw00, SYSNR=00 
LOCATION CPIC (TCP/IP) on local host 
ERROR SNCERR_UNKNOWN_MECH 
SncPImportPrName() parsing error 
name="p/sapsso:CN=SNC_BW3,OU=SAPBasis,O=example,C=DE" 
TIME Wed Nov 09 10:25:44 2022 
RELEASE 720 
COMPONENT SNC (Secure Network Communication) 
VERSION 5 
RC -38 
MODULE sncxxall.c 
LINE 2207 
DETAIL SncPSetNewName 
COUNTER

Connection refused
partner not reached

-------------------------
AppVersion: 22.2.2 - Branch:  - ChangeSet:  - ReleaseDate: 2022.11.8
2022.12.01|13:56:34
ERPConnect.CommunicationException: RfcOpenConnection failed(RFC_COMMUNICATION_FAILURE): 
LOCATION    CPIC (TCP/IP) on local host INT-SDVPC2009 with Unicode
ERROR       partner '10.201.162.53:3307' not reached
TIME        Thu Dec 01 13:56:34 2022
RELEASE     721
COMPONENT   NI (network interface)
VERSION     40
RC          -10
MODULE      nixxi.cpp
LINE        3289
DETAIL      NiPConnect2: 10.201.162.53:3307
SYSTEM CALL connect
ERRNO       10061
ERRNO TEXT  WSAECONNREFUSED: Connection refused
COUNTER     2

   bei ERPConnect.NW.NwApi.Connect(RFC_CONNECTION_PARAMETER[] parameters)
   bei ERPConnect.NW.NwClient.Connect(RFC_CONNECTION_PARAMETER[] parameters)
   bei ERPConnect.NW.NwClient.ERPConnect.IClient.Connect(Boolean loadBalancing)
   bei ERPConnect.R3Connection.Open(Boolean useLoadBalancing)
   bei ProjectB.SAPConnections.Bw.BwConnection.OpenSafe(Boolean useLoadBalancing)
   bei ProjectB.SAPConnections.Bw.SapConnectionOpener.GetOpenConnectionHavingDoubleConnectPossibilityInSetRouterCase()

RfcOpenConnection failed(RFC_COMMUNICATION_FAILURE): 
LOCATION    CPIC (TCP/IP) on local host INT-SDVPC2009 with Unicode
ERROR       partner '10.201.162.53:3307' not reached
TIME        Thu Dec 01 13:56:34 2022
RELEASE     721
COMPONENT   NI (network interface)
VERSION     40
RC          -10
MODULE      nixxi.cpp
LINE        3289
DETAIL      NiPConnect2: 10.201.162.53:3307
SYSTEM CALL connect
ERRNO       10061
ERRNO TEXT  WSAECONNREFUSED: Connection refused
COUNTER     2

Solution (RFC Library)

Switch to NWRFC or to LIBRFC and try the connection again.
Sometimes your SAP-Basis only allows one of the RFC protocols.

RFC Library

Solution (double-check parameters)

Can you spot the difference in this example? A simple typo can let the connection to fail.
We need the correct values from your SAP GUI Logon.

Solution (Connection Tester)

If you are unsure of your current SAP login parameters, you can use our tool 'Connection Tester'.

Input your SAP login parameter and press "Check connection".
If the 'Results'-window shows "Connection works"
Forward your parameter to us, which then will be reflected in your license file.

Continue here: Connection Tester

Solution (missing DLL files) (<v20.2)

Paste missing RFC DLL files into your windows folder.

How-To: LIBRFC NWRFC - External Library DLL files