"Total Client Unsuccessful" refers to the total number of unsuccessful client ThreatEx sessions. A session is considered unsuccessful if the number of packets sent does NOT equal the number of packets received.
"Total Server Unsuccessful" refers to the total number of unsuccessful server ThreatEx sessions. A session is considered unsuccessful if the number of packets sent does NOT equal the number of packets received.
For complete details on all the ThreatEx results, please open the online help using the F1 key from within the Avalanche GUI and then search on "ThreatEx Results"