title: AVAudioPlayer sound not playing
body: <p>In iOS 8/Xcode 6 I had a function that included a sound effect. It no longer works in iOS 9 after changing the code multiple times. This is what I've tried:</p>
  
  <p>Original: </p>
  
  <pre><code>let bangSoundEffect = SKAction.playSoundFileNamed("Bang.mp3", waitForCompletion: false)
          runAction(bangSoundEffect)
  </code></pre>
  
  <p>Other attempt:</p>
  
  <pre><code>self.runAction(SKAction.playSoundFileNamed("Bang.mp3", waitForCompletion: false))
  </code></pre>
  
  <p>Also: </p>
  
  <pre><code>func playRocketExplosionSound(filename: String) {
              let url = NSBundle.mainBundle().URLForResource(
                  filename, withExtension: nil)
              if (url == nil) {
                  print("Could not find file: \(filename)")
                  return }
              var error: NSError? = nil
              do {
                  backgroundMusicPlayer =
                      try AVAudioPlayer(contentsOfURL: url!)
              } catch let error1 as NSError {
                  error = error1
                  backgroundMusicPlayer = nil
              }
              if backgroundMusicPlayer == nil {
                  print("Could not create audio player: \(error!)")
                  return}
              backgroundMusicPlayer.numberOfLoops = 1
              backgroundMusicPlayer.prepareToPlay()
              backgroundMusicPlayer.play() }
  
  
  
  playRocketExplosionSound("Bang.mp3")
  </code></pre>
  
  <p>I'm pulling my hair out. I'm using the same code in a different scene for another sound effect and it works fine!! What's going wrong? 
  I've noticed that the sound effect begins to play sometimes in the simulator, however it doesn't complete and throws this error: </p>
  
  <pre><code>2015-09-24 19:12:14.554 APPNAME[4982:270835] 19:12:14.553 ERROR:    177: timed out after 0.012s (735 736); mMajorChangePending=0
  </code></pre>
  
  <p>It doesn't work at all on actual devices. </p>
  
  <p>What is the problem? :'(</p>