title: SignalR Error: Failed to start the connection: Error: None of the transports supported by the client are supported by the server
body: <p>I am trying to use SignalR in my .NET CORE 3.1 webapi(server) and angular 10(client) project. API (https://localhost:44305/api) and client angular (https://localhost:44305/user/signup) project shares same domain. This is how I have setup signalR in the server side: <br/></p>
  <ol>
  <li><p>I have created Hub class<br/></p>
  <pre><code>using Microsoft.AspNetCore.SignalR;
  namespace Web.Hubs
  {
      public class ResponseHub : Hub
      {
      }
  }
  </code></pre>
  </li>
  <li><p>In Startup.cs class, added services.AddSignalR() in the ConfigureService method. And Enabled CORS like :<br/></p>
  <pre><code>            services.AddCors(options =&gt;{
                  options.AddPolicy(MyAllowSpecificOrigins,
                  builder =&gt;
                  {
                      builder
                      .WithOrigins(Configuration.GetValue&lt;string&gt;(&quot;https://localhost:44305&quot;))
                      .AllowAnyHeader()
                      .AllowAnyMethod()
                      .AllowCredentials();
                  });
              });
  
  </code></pre>
  </li>
  </ol>
  <p><br/> And added following lines in configure method : <br/></p>
  <pre><code> app.UseEndpoints(endpoints =&gt;
              {
                 
                  endpoints.MapControllerRoute(
                      name: &quot;default&quot;,
                      pattern: &quot;{controller}/{action=Index}/{id?}&quot;);
                  endpoints.MapHub&lt;ResponseHub&gt;(&quot;/userdetails/response&quot;);
              });
  </code></pre>
  <p>In the client side,</p>
  <ol>
  <li><p>I have installed &quot;@microsoft/signalr&quot;: &quot;^3.1.9&quot; package in the angular project.</p>
  </li>
  <li><p>created service for the signalR like :</p>
  <pre><code>import { Signalrresponse } from &quot;./signalrresponse&quot;;
  import { Router } from &quot;@angular/router&quot;;
  import * as signalR from '@microsoft/signalr'; 
  
  @Injectable({
      providedIn: 'root'
  })
  export class SignalRService{
      constructor(private router: Router){}
   public data : Signalrresponse;
   private hubConnection: signalR.HubConnection
      public startConnection = () =&gt;{
          this.hubConnection = new signalR.HubConnectionBuilder()
                                  .withUrl(&quot;https://localhost:44305/api/userdetails/response&quot;)
                                  .build();
          this.hubConnection
              .start()
              .then(() =&gt; console.log(&quot;Connection Started&quot;))
              .catch(err =&gt; console.log('Error while starting connection: ' + err))
      }
  
      public addTransferChartDataListener = () =&gt;{
          this.hubConnection.on('changestatus',(data)=&gt;{
              console.log(&quot;Received data&quot;);
              this.data = data;
          })
      }
  }
  
  </code></pre>
  </li>
  </ol>
  <p>I am getting error while trying to establish connection from the client side. Error message : <strong>Error: Failed to start the connection: Error: None of the transports supported by the client are supported by the server.</strong><br/>
  Please help me in fixing this.<br/>
  Thanks.</p>