mp3 file wont play

"Won't play" is a little vague.

if "file not found" or "unable to open," or player doesn't even fire up, like crash in the background, suspect weird ^file name.

if "format not supported" you may have a corrupted file, or codec not supported by your player.

The best place to resolve such problem is a PC, if it doesn't play there it should give you more feedback as to what it wants.