Why are Blazor pages not firing in my ASP.Net app-CodePudding

I'm writing an ASP.Net Core app based on Freeman's book. And while adding Blazor pages, I got a problem. When you try to go to pages that Blazor is connected to, nothing is displayed on them.

The browser console shows these errors:

Error: System.NullReferenceException: Object reference not set to an instance of an object. at Microsoft.AspNetCore.Components.Routing.Router.Refresh(Boolean isNavigationIntercepted) at Microsoft.AspNetCore.Components.Routing.Router.SetParametersAsync(ParameterView parameters)

My Routed.razor file:

<Router AppAssembly="@typeof(Program).Assembly"
    AdditionalAssemblies="new[]{typeof(Program).Assembly}">
<Found>
    <RouteView RouteData="@context" DefaultLayout="typeof(AdminLayout)" />
</Found>
<NotFound>
    <h4 >
        No Matching Route Found
    </h4>
</NotFound>

What could be the problem?

I also add a link to the repository of my project: