Apple Remote has lost connection to your AppleTV.
Have you tried the IT Crowd "Have you tried turning it off and on again?"
https://www.youtube.com/watch?v=fU14GSc_mzA
You should be able to press and hold the TV/Control button for 5 seconds.
Let go of buttons within 5-10 seconds the remote should reboot and then should reconnect.
If it still does not work...
Hold the Menu and + volume button for 5 seconds close to the AppleTV.
