Unable to play dvd disc in dvd player

Question

I purchased a amphion mediaworks dvd player S99 two years ago and have found it generally reliable. I recently tried to play a dvd disc [office depot dvd-R] which I burned on a Ativa external dvd burner but the message "no disc" keeps coming up on the screen - indicating that the player can not recognize the disc. What is the problem and how do I correct it ? Thanks.