System.ArgumentNullException:Value cannot be null

Guest User

6y4.1k.NET

Hi Team

I am facing this issue on my IdentityConfig.cs using asp.net mvc to build user login registration. How do i fix this issue? Please assist me, thanks.

public class ApplicationSignInManager : SignInManagerstring>
{
public ApplicationSignInManager(ApplicationUserManager userManager, IAuthenticationManager authenticationManager)
: base(userManager, authenticationManager) // System exception here.
{
}
public override Task CreateUserIdentityAsync(ApplicationUser user)
{
return user.GenerateUserIdentityAsync((ApplicationUserManager)UserManager);
}
public static ApplicationSignInManager Create(IdentityFactoryOptions options, IOwinContext context)
{
return new ApplicationSignInManager(context.GetUserManager(), context.Authentication);
}
}

8 Replies

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Guest User6y ago
Hi Swamy will inbox you IP address for my AnyDesk
Viswanatha Swamy6y ago
Is there a way you can do screen share? we can hunt the issue down.
Guest User6y ago
Hi Swamy

After debugging i found out the following error and when adding it to watch.
Viswanatha Swamy6y ago
Hello,
Could you please place a debugger inside the Application Sign In Manager and put the first parameter in to watch? Let's see whether it gives us an object OR null. Many thanks.
Guest User6y ago
Hi VIswanatha
I did and called it Startup.Auth.cs file under App_Start folder and its calling the relevant namespace.
using System;
using Microsoft.AspNet.Identity;
using Microsoft.AspNet.Identity.Owin;
using Microsoft.Owin;
using Microsoft.Owin.Security.Cookies;
using Microsoft.Owin.Security.Google;
using Owin;
using eNtsaTrainingRegistration.Models;

namespace eNtsaTrainingRegistration
{
    public partial class Startup
    {
        public void ConfigureAuth(IAppBuilder app)
        {
            app.CreatePerOwinContext(ApplicationDbContext.Create);
            app.CreatePerOwinContext(ApplicationSignInManager.Create);
            app.CreatePerOwinContext(ApplicationUserManager.Create);
            app.CreatePerOwinContext(ApplicationRoleManager.Create);



            app.UseCookieAuthentication(new CookieAuthenticationOptions
            {
                AuthenticationType = DefaultAuthenticationTypes.ApplicationCookie,
                LoginPath = new PathString("/login"),
                Provider = new CookieAuthenticationProvider
                {
                    OnValidateIdentity = SecurityStampValidator.OnValidateIdentity(
                        validateInterval:TimeSpan.FromMinutes(30),
                        regenerateIdentity:(manager, user) => user.GenerateUserIdentityAsync(manager))
                }
            });

            app.UseExternalSignInCookie(DefaultAuthenticationTypes.ExternalCookie);

            app.UseTwoFactorSignInCookie(DefaultAuthenticationTypes.TwoFactorCookie, TimeSpan.FromMinutes(5));

            app.UseTwoFactorRememberBrowserCookie(DefaultAuthenticationTypes.TwoFactorRememberBrowserCookie);
        }
    }
}
Viswanatha Swamy6y ago
When we are seeing the userManager is null. I am assuming that it is not able to load it using dependency injection. Could you please verify your Start Up class
public partial class Startup

    {

        // For more information on configuring authentication, please visit http://go.microsoft.com/fwlink/?LinkId=301864

        public void ConfigureAuth(IAppBuilder app)

        {

            // Configure the db context, user manager and signin manager to use a single instance per request

            app.CreatePerOwinContext(ApplicationDbContext.Create);

            app.CreatePerOwinContext(ApplicationUserManager.Create);

            app.CreatePerOwinContext(ApplicationSignInManager.Create);
      }
}
Guest User6y ago
1. using System;
2. using System.Collections.Generic;
3. using System.Linq;
4. using System.Web;
5. using Owin;
6. using Microsoft.Owin;
8. [assembly:OwinStartup(typeof(eNtsaTrainingRegistration.Startup))]
9. namespace eNtsaTrainingRegistration
10. {
11. public partial class Startup
12. {
13. public void Configuration(IAppBuilder app)
14. {
15. ConfigureAuth(app);
16. }
17. }
18. }

Viswanatha Swamy6y ago

Good evening.

Could you please verify 1. you have configured User Manager and ApplicationSignInManager inside the Startup class.

public void ConfigureAuth(IAppBuilder app)
{
// Configure the db context, user manager and signin manager to use a single instance per request
}