By copied disc what do you mean?
Do you mean as in you copied a fully encoded DVD/VCD/whatever, and then tried to play it on your player?
Or do you mean you just copied a DVD/CD with a video file burned onto it? If that is the case, then your DVD player won't play it, if the other is the case then your player should be able to play it, otherwise it is not a good disc.
If you did just copy a disc with a video file just burned onto it like an ordinay file, and the video happened to be encoded with the DivXcodec, then your player will need to support the playback of datadiscs with DivX video files on it.
Should you find that the video is DivX, and your player does not support it, then you would need to copy the video file to your comp. and then encode it into DVD or whatever, using a DVD authoring tool like ConvertXtoDVD or Nero Vision, DVD Santa (not reccommended) etc.
EDIT: Simply burning a file onto disc is not enough for it to be able to be played by a DVD player. Unless if it is an .ISO or any other image file, then for such cases programs like Nero Burning Rom, or PowerISO, Daemon Tools etc. should be used. Or DVD Decrypter.
