Either the machine could not be woken up or it did not respond.
Source: Remote Wake Up
Severity: Important
Explanation: The remote node was not in the soft-off power state.
Explanation: The network interface card on the remote node is not Wake on LAN enabled.
Explanation: The remote node did not get powered up.
Explanation: The remote node got powered up, but the Wake on LAN Status Agent did not start.
When you install the Remote Management Agent, the Wake on LAN Status Agent is also installed. The Wake on LAN Status Agent responds to the magic packet it receives. See Installing the Remote Management Component.
Explanation: The remote node got powered up and the status agent started, but the agent was not able to send a response.
Action: Ensure that the prerequisites for Remote wake up are met. See Understanding Remote Wake Up.