AuthenticationManager.GetExternalLoginInfoAsync () returns null on Facebook

I developed a mvc 5 app and I am using facebook login using External callback, it worked well but now it doesn't work and I can't find the actual problem. And I find out why AuthenticationManager.GetExternalLoginInfoAsync (); returns null. I've used all most of the solutions in my application, but still have this problem. I delete the session and set cookies, but not getting executed.

I installed Facebook 6.4.0 from nuget in order to use FacebookClient to receive user generated events from facebook, but still it works, but I don't know what happened, I know it doesn't work and returns null.

In Startup.Auth

app.UseCookieAuthentication(new CookieAuthenticationOptions
        {
            AuthenticationType = DefaultAuthenticationTypes.ApplicationCookie,
            LoginPath = new PathString("/Account/Login"),
            Provider = new CookieAuthenticationProvider
            {
                // Enables the application to validate the security stamp when the user logs in.
                // This is a security feature which is used when you change a password or add an external login to your account.  
                OnValidateIdentity = SecurityStampValidator.OnValidateIdentity<ApplicationUserManager, ApplicationUser>(
                    validateInterval: TimeSpan.FromDays(1),
                    regenerateIdentity: (manager, user) => user.GenerateUserIdentityAsync(manager))
            },
            ExpireTimeSpan = TimeSpan.FromDays(2)
        });
        app.UseExternalSignInCookie(DefaultAuthenticationTypes.ExternalCookie);

      

        
        
        
      

    

Set Facebook app secret id and app in Startup.Auth

app.UseFacebookAuthentication(
    appId: "my app id",
    appSecret: "my app secret"
 );

      

        
        
        
      

    

In login I am using this below code.

[AllowAnonymous]
public async Task<ActionResult> ExternalLoginCallback(string returnUrl)
{            
    var loginInfo = await AuthenticationManager.GetExternalLoginInfoAsync();
    if (loginInfo == null)
    {
        return RedirectToAction("Login");
    }
}