title: Custom Speech TTS samples return "HTTP/1.1 503 Synthesis failed. StatusCode: Unavailable, Details: Connect Failed"
body: <p>When trying to run the samples provided on the "Custom Speech" endpoint page, I've come across two issues.</p>
  
  <ol>
  <li><p>When running it as provided, I get a <code>400 Bad Request</code> because the voice with name <code>Foo Bar</code> cannot be found. Replacing <code>&lt;voice name="Foo Bar"&gt;</code> with <code>&lt;voice&gt;</code> in the SSML I send to the service resolved this so far.</p></li>
  <li><p>Now I unfortunately get the following HTTP response (either in my browser's dev console when using the dialog on the Custom Speech website or via a manual HTTP call with my http client of choice):</p></li>
  </ol>
  
  <pre><code>HTTP/1.1 503 Synthesis failed. StatusCode: Unavailable, Details: Connect Failed.
  Content-Type: text/xml
  X-MSEdge-Ref: Ref A: 1FB8BE38F3034E6781319BEDB3570D5D Ref B: FRAEDGE1113 Ref C: 2019-12-11T11:43:41Z
  Date: Wed, 11 Dec 2019 11:43:43 GMT
  Content-Length: 0
  </code></pre>
  
  <p>The C# nuget library throws no exceptions, it just returns a 0 bytes.</p>
  
  <p>Is there anything I have to keep in mind when setting this up to get custom TTS or might the service have issues? We're running a S0 instance and setting up multiple deployment endpoints didn't help as well. All parts have "succeeded" according to the Speech Studio interface.</p>
  
  <p>Thanks in advance for help :)</p>