title: Play sound with AVAudioPlayer and a valid URL
body: <p>I have a sound file recorded on my iPad. This file is saved in the documents directory. Now I want to play this sound, but I get an error.</p>
  <p>I want to play sound like this:</p>
  <pre><code>NSURL *soundFileURL = [NSURL URLWithString:ulrString];
  _audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:soundFileURL error:&amp;err];
  </code></pre>
  <p>soundFileURL is:</p>
  <pre><code>Printing description of soundFileURL:
  /var/mobile/Applications/1824FDFA-18D7-472F-8C4D-16270372F9C9/Documents/Aufnahme-M-bi-1-7.m4a
  (lldb) 
  </code></pre>
  <p>But I get an error:</p>
  <pre><code>Error Domain=NSOSStatusErrorDomain Code=1685348671 &quot;The operation couldn’t be completed. (OSStatus error 1685348671.)&quot;
  </code></pre>
  <p>I have also tried following path to the sound file:</p>
  <pre><code>@&quot;file:///var/mobile/Applications/1824FDFA-18D7-472F-8C4D-16270372F9C9/Documents/Aufnahme-M-bi-1-7.m4a&quot;
  </code></pre>
  <p>But this also does't work :/</p>