Authentication-failed for inbound AS2 message; verification failed: Expected signer info not found

Symptom

After updating trading partner profile with a new AS2 certificate and receiving an AS2 data, EDIINT Pipeline Parse step completed with error and the Advanced Status shows Authentication-failed message.

Same message also shows in the Status Report and Process Data info.

Turning on logging for EDIINT.log (Operations > System > Logs > List and Go! > click the paper/pencil symbol besides EDIINT > select on > Save), asking trading partner to send another data, user noticed another error message indicating

verification failed: Expected signer info not found

Searching through Pipeline.log, user also sees the same Expected signer info not found message.

Information from Pipeline.log also shows that GIS/SI is expecting a certificate used by trading partner to sign the data that was sent over to be encrypted with a certain serial number as per trading partner AS2 setting;

while some other certificate's serial number was found.  These serial numbers are in hex mode.  One can normally see the serial number in hex mode when double clicking on trading partner's digital certificate and click Details tab.

1.  Authentication-failed

2.  verification failed: Expected signer info not found