cannot use television as NOT PROGRAMMED sign on screen

[Scully3]

Cannot used television because NOT PROGRAMMED on screen

[xenon81]

That's a problem with your TV. It sounds like it's on the wrong input. Use your TV remote (not Sky remote) to switch it to HDMI1 or whichever input Sky is connected to. 

[TimmyBGood]

@Scully3 

As @xenon81 indicates, 'NOT PROGRAMMED' is a distinctly unhelpful message being generated by the television set which is supposed to indicate that it's trying to display content arriving through a built-in digital terrestrial tuner, but hasn't been able to successfully scan for channels (typically because there's no aerial attached)

Quite why television UI designers think this is useful wording remains a mystery.