In the most recent connector pack, there is revision 4 of an SNMP connector for SolarWinds Orion and Virtualization Manager. By default, it reads from the snmptrapfmt.log. Have you configured this connector on your appliance?
It should be noted that we release updated connectors every 2 to 4 weeks, so it's a good idea to check the Solarwinds Customer Portal at least once a month and download and install the latest connector updates. Directions on how to get and apply the update can be found here: