During an attempt to establish a secure connection, the partner machine did not return an expected certificate. The machine that initiated the connection cannot validate the identity of the partner machine.
The secure connection fails.
Check the configuration parameters SSL_REQ_SRVR_CERT and SSL_REQ_CLNT_CERT on the initiating machine and on the partner machine. If a PowerExchange Listener is configured with SSL_REQ_CLNT_CERT=N, client certificates are not requested or validated.