Previous to CAS 1.3.7, CAS only supports up to two SNMP trap destinations. The addition of a third SNMP trap destination results in SNMP service restarts, CAS restarts, and onboard statistics/diagnostics not displaying.
The administration guide for Content Analysis states the following:
It is confirmed that two SNMP servers will function as intended. Adding a third SNMP trap destination will cause problems with SNMP services, and may cause SNMP to hang and restart the device. This issue has been resolved in CAS 1.3.7.
Specify up to two trap destinations until you can upgrade to 1.3.7