title: await faceClient.Face.DetectWithStreamAsync returning null
body: <p>I am trying to run Microsoft's 'Create a WPF app to display face data in an image' (<a href="https://docs.microsoft.com/en-us/azure/cognitive-services/face/tutorials/faceapiincsharptutorial" rel="nofollow noreferrer">https://docs.microsoft.com/en-us/azure/cognitive-services/face/tutorials/faceapiincsharptutorial</a>) but everything I try to use an image to detect faces it will return a Null error (No faces found).</p>
  
  <p>I have downloaded the Windows tutorial project files from github as well as trying a simplified version here: <a href="https://carldesouza.com/building-an-azure-cognitive-services-face-app-part-1-face-recognition/" rel="nofollow noreferrer">https://carldesouza.com/building-an-azure-cognitive-services-face-app-part-1-face-recognition/</a>, each with the same error. I have managed to create some ASP.Net Web applications that can detect faces as well as creating people groups using the same API key and Endpoint to detect specific people.</p>
  
  <p>The program seems to fail to detect faces at this bit of code:</p>
  
  <pre class="lang-cs prettyprint-override"><code>IList&lt;DetectedFace&gt; faceList =
                          await faceClient.Face.DetectWithStreamAsync(
                              imageFileStream, true, false, null);
  
  
  [AsyncStateMachine(typeof(&lt;DetectWithStreamAsync&gt;d__6))]
          public static Task&lt;IList&lt;DetectedFace&gt;&gt; DetectWithStreamAsync(this IFaceOperations operations, Stream image, bool? returnFaceId = true, bool? returnFaceLandmarks = false, IList&lt;FaceAttributeType&gt; returnFaceAttributes = null, CancellationToken cancellationToken = default);
  </code></pre>
  
  <p>The only error that I get from debugging is that this bit of code always return null and therefor does not detect any faces.</p>