title: SpeakerBox via CallKit on Xcode 8 beta 6
body: <p><a href="https://developer.apple.com/library/prerelease/content/samplecode/Speakerbox/Introduction/Intro.html" rel="nofollow">SpeakerBox</a> application made by Apple doesn't work anymore after update to Xcode 8 beta 6.
  It logs an error:</p>
  
  <blockquote>
    <p>Error requesting transaction: Error
    Domain=com.apple.CallKit.error.requesttransaction Code=2 "(null)"</p>
  </blockquote>
  
  <p>Where Code=2 is a <a href="https://developer.apple.com/reference/callkit/cxerrorcoderequesttransactionerror/cxerrorcoderequesttransactionerrorunknowncallprovider?language=objc" rel="nofollow">CXErrorCodeRequestTransactionErrorUnknownCallProvider</a> error.</p>
  
  <p>Everything worked fine on Xcode 8 beta 4.</p>
  
  <p>Does anybody know what is happened there?</p>