.Net core 3.1 Simple View returning internal server error 500

Question

Recently I asked a question about exposing a console app through a web browser. I received a very helpful answer and followed the instructions in the link provided, but then I can't seem to display a simple view, even when returning OK works fine:

Program.cs

class Program
{
    static void Main(string[] args)
    {
        var host = new WebHostBuilder()
        .UseKestrel()
        .UseContentRoot(Directory.GetCurrentDirectory())
        .UseStartup<Startup>()
        .Build();

        host.Run();
    }
}

Startup.cs

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc();
    }

    public void Configure(IApplicationBuilder app)
    {
        app.UseMvc();
    }
}

Controller.cs

public class HomeController : Controller
{
    [Route("home/Index")]
    public IActionResult Index()
    {
        //return Ok("Hello from a controller");   //THIS WORKS 

        IndexModel data = new IndexModel();         //THIS RETURNS INTERNAL SERVER ERROR 500
        data.Title = "THIS";
        data.Message = "MESSAGE";
        return View(data);
    }
}

The Model and index:

public class IndexModel
{
    public string Title { get; set; }
    public string Message { get; set; }
}

@page
@model ConsoleApp1.Views.Home.IndexModel
@{
}
<div>
    <p>@Model.Title</p>
    <p>@Model.Message</p>
</div>

This is the error i get when trying to display the view

Answer 1

Please notice that you are create a asp.net-core-3.1 mvc project.

Your project structure should look like this:

Then change your Startup to:

 public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddControllersWithViews();
     
    }

    public void Configure(IApplicationBuilder app)
    {
        app.UseRouting();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapControllerRoute(
                name: "default",
                pattern: "{controller=Home}/{action=Index}/{id?}");
        });
    }
}

Then in your project.csproj.Change it to(notice that it's Sdk="Microsoft.NET.Sdk.Web") :

 <Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp3.1</TargetFramework>
    <PreserveCompilationContext />
  </PropertyGroup>

    <ItemGroup>
        <FrameworkReference Include="Microsoft.AspNetCore.App" />
    </ItemGroup>
</Project>