Updated March 24, 2017
Syslog messages are not visible or are not showing but the syslog packets are available in Wireshark.
All NPM versions
Syslog messages are blocked by Windows firewall.
Add new rules both inbound and outbound syslog messages.
Allow port UDP 514.
Restart the syslog service.
Note: This is also applicable to traps (UDP 162).