HttpContext.GetOwinContext().GetUserManager<ApplicationUserManager>() get this InvalidOperationException - asp.net

Question

I've used ASP.NET Identity 2 for creating a registration user logic, and I have an exception at HttpContext.GetOwinContext().GetUserManager().
What could be a problem? Thank you for any advise.
There is registration controller
public class AccountController : Controller
{
private ApplicationUserManager UserManager
{
get
{
return HttpContext.GetOwinContext().GetUserManager<ApplicationUserManager>();
}
}
public ActionResult Register()
{
return View();
}
[HttpPost]
public async Task<ActionResult> Register(RegisterUserModel model)
{
if (ModelState.IsValid)
{
AppUser user = new AppUser { UserName = model.Email, Email = model.Email };
IdentityResult result = await UserManager.CreateAsync(user);
if (result.Succeeded)
{
return RedirectToAction("Login", "Account");
}
else
{
foreach (string error in result.Errors)
{
ModelState.AddModelError("", error);
}
}
}
return View(model);
}
}
ApplicationUserManager logic
public class ApplicationUserManager : UserManager<AppUser>
{
public ApplicationUserManager(IUserStore<AppUser> store)
: base(store)
{
}
public static ApplicationUserManager Create(IdentityFactoryOptions<ApplicationUserManager> options,
IOwinContext context)
{
IdentificationContext db = context.Get<IdentificationContext>();
ApplicationUserManager manager = new ApplicationUserManager(new UserStore<AppUser>(db));
return manager;
}
}
Registration model
public class RegisterUserModel
{
[Required]
[StringLength(255)]
[RegularExpression(#"[A-Za-z0-9._%+-]+#[A-Za-z0-9.-]+\.[A-Za-z]{2,4}")]
public string Email { get; set; }
[Required]
[DataType(DataType.Password)]
[StringLength(255, MinimumLength = 5)]
public string Password { get; set; }
[Required]
[System.ComponentModel.DataAnnotations.Compare("Password")]
[DataType(DataType.Password)]
public string PasswordConfirm { get; set; }
}
Model that inherit from IdentitiyUSer model
public class AppUser : IdentityUser
{
public AppUser() { }
}
Startup class
public void Configuration(IAppBuilder app)
{
app.CreatePerOwinContext<IdentificationContext>(IdentificationContext.Create);
app.CreatePerOwinContext<ApplicationUserManager>(ApplicationUserManager.Create);
app.UseCookieAuthentication(new CookieAuthenticationOptions
{
AuthenticationType = DefaultAuthenticationTypes.ApplicationCookie,
LoginPath = new PathString("/Account/Login"),
});
}
There is an output of exception
enter image description here

Answer 1

You need to add setting (owin:AutomaticAppStartup) in web.config
<add key="owin:AutomaticAppStartup" value="true"/>
If it still doesn't work, add below setting specifying your startup class. This is because the default convention for the Startup class is [AssemblyName].Startup. If you're no longer following that convention you'll need to specify the full name of your Startup class in the Web.Config.
<add key="owin:AppStartup" value="[Namespace].Startup, [AssemblyName]" />
Hope it helps.