title: Application is running inside IIS process but is not configured to use IIS server .NET Core 3.0
body: <p>I have migrated our application from .NET Core 2.2 to version 3.0. Actually I created the new application in 3.0 from scratch and then copied source code files. Everything looks great but when I try to run the application within Visual Studio 2019 I get the exception: </p>
  
  <blockquote>
    <p>Application is running inside IIS process but is not configured to use IIS server</p>
  </blockquote>
  
  <p>Here is my Program.cs</p>
  
  <pre><code>public static class Program
  {
      public static void Main(string[] args)
      {
          CreateHostBuilder(args).Build().Run();
      }
  
      public static IHostBuilder CreateHostBuilder(string[] args) =&gt;
          Host.CreateDefaultBuilder(args)
              .ConfigureWebHostDefaults(webBuilder =&gt;
              {
                  webBuilder.UseContentRoot(Directory.GetCurrentDirectory());
                  webBuilder.UseKestrel();
                  webBuilder.UseIISIntegration();
                  webBuilder.UseStartup&lt;Startup&gt;();
              });
  }
  </code></pre>
  
  <p>The error occurs at the line: CreateHostBuilder(args).Build().Run();
  It worked fine in .NET Core 2.2 but it doesn't want to run as 3.0. I cannot find anything else that should be done. Something new in the Startup.cs? I don't know.</p>