DVR will record from TV but won't play on another DVD

Hi, I have two DVDs. I recorded from the tv and it plays back prefectly fine. But when I put it into another DVD it won’t play. Its says “Disc Error”. HELP! What am I doing wrong? All I want is to record the Grey’s Anatomy finale so that my sister can see it! Nothing illegal.

Did you “finalize” the disc after recording? Not doing so can prevent the disc from playing in other players.

that did it! txs!