title: Blazor WebAssembly: The provided ContentType is not supported;
body: <p>I have installed the Blazor WebAssembly Example Project (WeatherForecast) today by the following command line:</p>
  <pre><code>dotnet new blazorwasm --hosted -o ProjectName
  </code></pre>
  <p>I started the SPA directly after the installation via Visual Studio 2019 in Debug Mode. The Browser is: Chrome. The Browser shows the app, but when I select the Nav Menu &quot;Fetch Data&quot; then nothing happens. Chrome shows 1 Error:</p>
  <pre><code>Microsoft.AspNetCore.Components.WebAssembly.Rendering.WebAssemblyRenderer[100]
        Unhandled exception rendering component: The provided ContentType is not supported; the supported types are 'application/json' and the structured syntax suffix 'application/+json'.
  System.NotSupportedException: The provided ContentType is not supported; the supported types are 'application/json' and the structured syntax suffix 'application/+json'.
    at System.Net.Http.Json.HttpContentJsonExtensions.ValidateContent (System.Net.Http.HttpContent content) &lt;0x2e87f38 + 0x0009a&gt; in &lt;filename unknown&gt;:0 
    at System.Net.Http.Json.HttpContentJsonExtensions.ReadFromJsonAsync[T] (System.Net.Http.HttpContent content, System.Text.Json.JsonSerializerOptions options, System.Threading.CancellationToken cancellationToken) &lt;0x2e87d30 + 0x00006&gt; in &lt;filename unknown&gt;:0 
    at System.Net.Http.Json.HttpClientJsonExtensions.GetFromJsonAsyncCore[T] (System.Threading.Tasks.Task`1[TResult] taskResponse, System.Text.Json.JsonSerializerOptions options, System.Threading.CancellationToken cancellationToken) &lt;0x2e40838 + 0x0011c&gt; in &lt;filename unknown&gt;:0 
    at BlazorIssue.Client.Pages.FetchData.OnInitializedAsync () [0x00033] in D:\Projects\BlazorIssue\Client\Pages\FetchData.razor:43 
    at Microsoft.AspNetCore.Components.ComponentBase.RunInitAndSetParametersAsync () &lt;0x2b8cb98 + 0x0013a&gt; in &lt;filename unknown&gt;:0 
    at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask (System.Threading.Tasks.Task taskToHandle) &lt;0x2dd8340 + 0x000b6&gt; in &lt;filename unknown&gt;:0 
  </code></pre>
  <p>Chrome shows the following Request Headers:</p>
  <p><a href="https://i.stack.imgur.com/9wKS0.png" rel="noreferrer"><img src="https://i.stack.imgur.com/9wKS0.png" alt="Blazor WebAssembly Request Headers" /></a></p>
  <p>Context-Information:</p>
  <ul>
  <li>Chrome: V83.0.4103.61 (64bit)</li>
  <li>Blazor: V3.2.0</li>
  <li>Visual Studio: V16.6.0</li>
  <li>DotNet V3.1.300</li>
  <li>DotNet SDK: V3.1.300</li>
  </ul>
  <p>That is curious because a fresh installation of this example project worked yesterday with no problems.</p>