Certificate Exception
If this exception appears in the server.log file stored on the IoT FND server when a FAR attempts to register with IoT FND, the cgms_keystore file does not contain the CA server certificates or the CA certificates that were imported into the cgms_keystore file are incorrect:
SSLException: Received fatal alert: unknown_ca
For information about how to import certificates into the cgms_keystore file, see “Generating and Installing Certificates in the Cisco IoT Installation Guide, 4.0.x and greater.