cannot access apple tv. it say authentication error. how do i authenticate?

I have this question too

exactly , the message is on connecting Apple Tv on the Tv ;

Connexion impossible

AMD-Action:authenticate:SP

Thanks for help

I have the same thing. have you solved it yet?

I Also have this message, so what does it mean and how do we stop it coming up all the time? It shows itself when I try to access Youtube. Does this mean Mac has to be turned on?