title: iOS - AudioUnitInitialize returns error code 561017449
body: <p>I have an app in the App Store which uses AudioUnit for recording audio.</p>
  
  <p>About once a week or so I am seeing that for some users in the wild the call to <code>AudioUnitInitialize</code> fails with the error code 561017449 which is also 0x21707269 or "irp!".</p>
  
  <p>What does this error code mean?  I've been unable to find it documented.  Also:</p>
  
  <pre><code>~$ macerror 561017449
  Unknown error (561017449) at /usr/bin/macerror5.16 line 40, &lt;DATA&gt; line 1.
  </code></pre>
  
  <p>There have been few instances of this issue, but so far there appears to be no pattern of commonality as far as device and OS version goes.</p>
  
  <p>I'm not including code as I don't think that will be helpful just yet.  The code is working on variety of devices already.  At this time I'm most interested in learning details about this specific error.</p>
  
  <p>Thanks!</p>