This question is related to this one.
I managed to modify my code to use SoundPool instead of AudioManager. Know it works more or less.
public class
From what I have read if you try to play the sound right after initializing it, it won't be ready and you will get this error. You could make a loading page and just wait for a few seconds until you are sure the sound has loaded.
Also make sure your filesize isn't over 1048576 bytes, thats the limitation for Soundpool. If you want to play background music or something i think you have to use media player.