I recently installed the latest monitoring agent on a primary and a failover exchange server, then switched from SNMP polling method to Agent. The application templates on both are identical, and were running fine without error via WMI, but with agent polling enabled, the template applied I have which looks at 'exchange mailbox' metrics, portions of the last few components fails with error: "PDH error occured. HResult: The data item has been added to the query but has not been validated nor accessed. No other status information on this data item is available" .
This error is consistent with both primary and secondary server.
I did also note the long response time now in Orion for these nodes (over. 650ms), but I thought that bug was for passive agents, not active. I set these agents up as active/agent initiated.