Why does my mp4 player say 'format error' when I add music to it? I've added mp3 format music from Ares before, but now it shows 'format error'. What can I do? I really want to add more music.

The file could be DRM protected.

But try this to get a file that is now on your mp4 cut it and place it on your pc. So that it isn't on your mp4 anymore but on your pc. And then try to add that file on your mp4 again. I think you will manage this. If not your mp4 is broken. And the file you just want to add is probably in the wrong format. Like you downloaded it as a .wav file but change the name into .mp3. It doesn't work like that you need software to change file extensions

I hope this helps you.

You have to make sure you r getting the right kind of music in the right format. My mp4 would not let me sync songs from itunes and it said the same thing......hope it helps!