After upgrading to SAG / SNL 7.0.20, you'll get an LMAC authentication error during FIN Login FIN processing is no longer possible.
After upgrading to SAG / SNL 7.0.20, FIN Login fails with a DNFF4433E:
DNFF4433E 12/27/12 8:26:34 AM <OUName> DNF_FSM LT '': LMAC authentication failure with a received message from queue manager '<QMgr>', queue name '<Instance>.DNF_FSM_SLS.<LTName>'
This message indicates a mismatch of the LAU Keys configured on the SAG and in WBI-FN, even though both are identical.
A fix for this problem is now available from SWIFT with patch SAG 7.0.21.