title: MachMessagePort error when requesting access to address book
body: <p>I am trying to load a few contacts from the address book. </p>
  
  <p>I create the address book in viewDidLoad and check for authorisation</p>
  
  <pre><code>if (!_addressBook) {
        CFErrorRef error=NULL;
        _addressBook=ABAddressBookCreateWithOptions(NULL, &amp;error);
      }
  </code></pre>
  
  <p>I then release it in dealloc</p>
  
  <pre><code>if (_addressBook) {
          CFRelease(_addressBook);
          _addressBook = NULL;
      }
  </code></pre>
  
  <p>But I still get the following error. </p>
  
  <pre><code>Error, could not create MachMessagePort for database doctor (com.apple.ABDatabaseDoctor)
  </code></pre>
  
  <p>Is it due to a problem in memory allocation, permissions, or something else entirely?</p>