错误CS0122由于其保护级别，“AuthenticationOptions”无法访问

Question

I was following this guide to write my own Katana authentication middleware .

Now I encountered a problem when I'm writing the AuthenticationOptions. I get an "inaccessible due to its protection level" when I inherent from Microsoft.Owin.Security.AuthenticationOptions. The thing is that this class is protected, so it should not be inaccessible? I have tried to do a clean and rebuild, but I still get the same error. I must be missing something?

My class:

using Microsoft.Owin;
using Microsoft.Owin.Security;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Dummy
{
    public class DummyAuthenticationOptions : AuthenticationOptions
    {
        public DummyAuthenticationOptions(string userName, string userId)
            : base(Constants.DefaultAuthenticationType)
        {
            Description.Caption = Constants.DefaultAuthenticationType;
            CallbackPath = new PathString("/signin-dummy");
            AuthenticationMode = AuthenticationMode.Passive;
            UserName = userName;
            UserId = userId;
        }

        public PathString CallbackPath { get; set; }

        public string UserName { get; set; }

        public string UserId { get; set; }

        public string SignInAsAuthenticationType { get; set; }

        public ISecureDataFormat<AuthenticationProperties> StateDataFormat { get; set; }
    }
}

Microsoft.Owin.Security.AuthenticationOptions:

namespace Microsoft.Owin.Security
{
    internal abstract class AuthenticationOptions
    {
        protected AuthenticationOptions(string authenticationType);

        public AuthenticationMode AuthenticationMode { get; set; }
        public string AuthenticationType { get; set; }
        public AuthenticationDescription Description { get; set; }
    }
}

Answer 1

The problem was that the AuthenticationOptions class was set to internal. I downgraded the Microsft.Owin.Security package from 3.0.1 to 2.0.1. Here the class is marked public so I was able to compile without problems.

Thanks to Dmitry Rotay