I suspect this has nothing to do with the Slingbox as it does not involve the TV. I would hazard a guess you may see the same message on your TV at home and something needs to be done to the cable/satellite box. You need someone at your house to look onto it.
You haven't told us how the M2 is connected, but if you used component cables and an HDMI cable to the TV then I would also suggest that your TV provider has implemented HDCP, so you need the TV on all the time (Did you test it before you went with the TV on ?). If that is so you need to rewire it when you get home to remove the HDMI cable and feed the TV from the component OUT plugs of the Slingbox.
Bottom line is that this is NOT a Slingbox-generated error so there is probably nothing you can do from Florida.