The use of the EventSentry Network Services (SYSLOG, SNMP trap, and Arp watch daemons) requires a minimum of 5 network device licenses. If you go into Tools > License management, do you have those licenses? If not, you can set the service to "Manual" startup type and you will no longer receive these warnings. You can do this by clicking on "Network Services" in the management console and then "Manual" button.
I hope this helps resolve your issue. If you do have the network device licenses, please let us know.