My DVD player suddenly says "wrong disc"

I own a relativly new Norcent DVD Player model number DP313 I was watching a movie and when it ended and I replaced it with another, sudden it says after trying to load....WRONG DISC. I have tried other disc even CD's and MP3. All of them get the same response. What else could be wrong. PS I even tried a disc cleaner cd
I'm stumped and frustrated so any advise would be nice. Thanks