title: midiOutOpen on Windows 10 using Microsoft GS Wavetable Synth fails
body: <p>I have an application that relies on the in built Microsoft GS Wavetable Synth. It has worked flawlessly on Windows XP, Vista, 7, 8 and 8.1. While the first call to midiOutOpen on Windows 10 works, subsequent calls result in error code 1, meaning 'Unspecified error'. The code is simple:</p>
  
  <pre><code>result = midiOutOpen(&amp;_midiOutHandle, midiOutputDevice, NULL, 0, CALLBACK_NULL);
  </code></pre>
  
  <p>Any ideas regarding how to resolve this hugely appreciated.</p>