If the last SNMP SET was rejected, for example with
SNMP Error: BadValue (SNMP Error 3), this object
should explain why the SET failed.
This string may be empty (size 0) if no explanation
is available.
If there have been no SET requests since boot-up, this
string should be empty (size 0).
In addition to this object, SET errors may also be found
in the nbsCmmcSysRunningLogMessageTable.