title: Microsoft.TeamFoundation.WorkItemTracking.WebApi failing to GetClient<WorkItemTrackingHttpClient>()
body: <p>I'm following the azure-devops-dotnet-samples CreateBugUsingClientLib() sample pretty closely, but</p>
  
  <pre><code>GetClient&lt;WorkItemTrackingHttpClient&gt;()
  </code></pre>
  
  <p>is throwing:</p>
  
  <p>InnerException:  {"Could not cast or convert from System.String to Microsoft.VisualStudio.Services.Identity.IdentityDescriptor."}   System.Exception {System.ArgumentException}</p>
  
  <p>Message:  "Error converting value \"Microsoft.IdentityModel.Claims.ClaimsIdentity;stuff\me@contoso.com\" to type 'Microsoft.VisualStudio.Services.Identity.IdentityDescriptor'. Path 'authenticatedUser.descriptor'</p>
  
  <p>The full sample is here: <a href="https://github.com/Microsoft/azure-devops-dotnet-samples/blob/master/ClientLibrary/Quickstarts/dotnet/WitQuickStarts/Samples/CreateBug.cs" rel="nofollow noreferrer">https://github.com/Microsoft/azure-devops-dotnet-samples/blob/master/ClientLibrary/Quickstarts/dotnet/WitQuickStarts/Samples/CreateBug.cs</a></p>
  
  <p>All my NuGets are up to date.</p>
  
  <pre><code>// string uri = "https://teams.visualstudio.com/defaultCollection/"
  // string pat = "personal access token";
  // string project = "Ateam";
  // string path = "autobug";
  // string title = "you broke it";
  // string steps = "you touched it";
  
  var patchDoc = new JsonPatchDocument
  {
      new JsonPatchOperation() { Operation = Operation.Add, Path = "/fields/System.Title", Value = title },
      new JsonPatchOperation() { Operation = Operation.Add, Path = "/fields/System.AreaPath", Value = path },
      new JsonPatchOperation() { Operation = Operation.Add, Path = "/fields/Microsoft.VSTS.TCM.ReproSteps", Value = steps },
      new JsonPatchOperation() { Operation = Operation.Add, Path = "/fields/Microsoft.VSTS.Common.Priority", Value = "2" },
      new JsonPatchOperation() { Operation = Operation.Add, Path = "/fields/Microsoft.VSTS.Common.Severity", Value = "2" }
  };
  
  var cred = new VssBasicCredential("", pat);
  var conn = new VssConnection(new Uri(uri), cred);
  var client = conn.GetClient&lt;WorkItemTrackingHttpClient&gt;();
  </code></pre>