Service reporting Invalid Class
If you receive an Invalid Class error for SAM services, it could be due to a number of issues including the incorrect polling method or issues with the WMI repository. If the following information does not resolve the issue, review information in our Success Center.
Verify the polling type
Services can be polled using RPC or WMI monitors. Verify the correct service is running for polling by navigating to Edit Application > RPC or WMI. If the correct monitor is used for polling, you may need to troubleshoot the monitors.
Repair the WMI Repository
If the WMI monitor is used for polling and returns an error of Invalid Class, you need to repair the WMI repository. You can also try switching the polling method for the node from WMI to RPC.