title: IOServiceOpen returns 0x10000003 (MACH_SEND_INVALID_DEST)
body: <p>When trying to open the service for a driver (with a user client per the <a href="https://developer.apple.com/library/mac/#samplecode/SimpleUserClient/Introduction/Intro.html" rel="nofollow">SimpleUserClient example</a>) I am writing, IOServiceOpen returns 0x10000003 (<code>MACH_SEND_INVALID_REQUEST</code>):</p>
  
  <pre><code>mach_port_t machPort = mach_task_self();
  kern_return_t kernResult;
  io_service_t service;
  
  classesToMatch = IOServiceNameMatching(DRIVER_NAME);
  
  kernResult = IOServiceGetMatchingServices(kIOMasterPortDefault, classesToMatch, &amp;iterator); 
  
  while ((service = IOIteratorNext(iterator)) != IO_OBJECT_NULL){
      kernResult = IOServiceOpen(service, machPort, 0, &amp;connect);
  
      if (kernResult != KERN_SUCCESS){
          //0x10000003 = MACH_SEND_INVALID_DEST causes a return false here
          fprintf(stderr, "IOServiceOpen returned 0x%08x - machPort is %lu\n"), kernResult, machPort);
          return false;
      }
  }
  </code></pre>
  
  <p>Therefore, the service is never opened.</p>