EDIT: Moved from EEPC forum, no response. I'm hoping some folks in ePO can help me out.
I think you will check the communication between the epo and Agent.
Checking the network communication .
Checking the Agent has received the agent wake up requestion after you do it in epo.
Wakeup Agent will use the 8081 port in your epo server.
and in the server task log report you can drop in the faild to see the reason when it show you Faild.
If your query has a null return this will fail. Bad programming. I just faked it by running another query to apply a tag to a discreet system that is also ways on.