WDM Agent: Invalid Command

I am receiving an error message when attempting to reboot or shutdown a T10 remotely using WDM. The error is instantly logged on the thin client:

WDM agent: invalid command

Has anyone seen this before? The device shows up (green) under devices in WDM and I can remote shadow just fine. I just can't send a reboot or shutdown command. Any help would be appreciated.

Thank you,

D