In my environment, I have SolarWinds Orion monitoring Windows Server 2008 R2 and Server 2012 boxes. Occasionally, monitors will flap or fail, even though the monitored item has not failed or met the failure criteria.
In the event log, I find a service restart and a failure to read the HKLM\SYSTEM\CurrentControlSet\Services\SNMP\Parameters\TrapConfiguration key.
The error in the event log is EventID 1500 in the System Log with an Event Source of SNMP and an error message of "The SNMP Service encountered an error while accessing the registry key SYSTEM\CurrentControlSet\Services\SNMP\Parameters\TrapConfiguration."
I found this support article which details the error and provides a workaround. The workaround creates the missing key.
I then created a GPO which has a Group Policy Preference to create at key if it does not exist.
I'm going to continue to monitor and see if that resolves the intermittent failures.
When I had this issue I found that the SNMP Traps service was not running. I started the SNMP Traps service and I no longer received the error and was able to successfully configure SNMP.
It's so annoying when even windows and the pc makers can't tell you what a problem is like this. In the end I just removed the entire snmp setups I had and did them over. Nothing was wrong with anything as I had been using the computer the exact same way as before it happened and it's running the same way after so the only solution I can assume is that a GLITCH IS A BITCH and just like rebooting your computer after a problem so should you reboot this too without any of the snmp settings on and then after rebooting go back and put them all in or at least the one(s) you use on your computer. There just isn't an answer and I worked on this computer for a week trying to find out what was wrong along with hours of searching for an answer. I hope it helps someone. Good Luck.