System.Management.ManagementException: Invalid class

You may see this error in your Windows event logs.

System.Management.ManagementException: Invalid class 
at System.Management.ManagementException.ThrowWithExtendedInfo(ManagementStatus errorCode) 
at System.Management.ManagementObjectCollection.ManagementObjectEnumerator.MoveNext() 
at BoxedIce.ServerDensity.Agent.Checks.ProcessCheck.ProcessStats() 
at BoxedIce.ServerDensity.Agent.Checks.ProcessCheck.DoCheck() 
at BoxedIce.ServerDensity.Agent.Agent.DoChecks()

This happens if the Windows performance counters are unavailable or disabled. To fix this, do the following:

1. Understand the consequences and backup your registry before making changes.
2. Run "regedit.exe"
3. Navigate to "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\PerfProc\Performance"
4. Ensure if you have a DWORD entry named "Disable Performance Counters" that if it was set to 1, that it is properly set to 0 (zero).
5. Reboot of server may be necessary.