All of sudden apple tv will not play my tv shows/movies on itunes. It says "The connected display is not authorized to play protected movies."...

All of sudden apple tv will not play my tv shows/movies on itunes. It says "The connected display is not authorized to play protected movies.

Can anyone help I have just bought alot of movies and tv shows and want to watch them with my family not just on my ipad!!!

Not sure why this has just started happening. have been using apple tv with my ipad for months and now it comes up with this error...

THanks