title: InvalidOperationException: An invalid request URI was provided. The request URI must either be an absolute URI or BaseAddress must be set
body: <p>I'm trying to connect to Cognitive Services Face API by using Connected Services in Visual Studio in Asp.net Core by following tutorial</p>
  
  <p><a href="https://docs.microsoft.com/en-us/azure/cognitive-services/face/vs-face-connected-service" rel="nofollow noreferrer">https://docs.microsoft.com/en-us/azure/cognitive-services/face/vs-face-connected-service</a>  </p>
  
  <p>but in executing the REST API Call    </p>
  
  <pre><code>var response = client.PostAsync(uri, content).Result;
  </code></pre>
  
  <p>i get this Error</p>
  
  <pre><code>System.InvalidOperationException: 'An invalid request URI was provided.
  The request URI must either be an absolute URI or BaseAddress must be set.
  </code></pre>
  
  <p>I have active subscription on azure and on cognitive services and API key is correct.</p>