Unauthorized: Logon failed due to server configuration.

Hi!
I am creating an ASP.NET Web Form. I deleted the default login, register, etc pages and created my own login page. I used this site for it: http://www.aspenrootsdevelopment.com/posts/ASPNET-Identity2.0-Custom-Database/.
The default program uses PasswordSigIn() method. If I use that, I have problem with the "Lockout". Instead of PasswordSignIn() I use SignInAsync() method. When I try to sign in it says: "Unauthorized: Logon failed due to server configuration. Verify that you have permission to view this directory or page based on the credentials you supplied and the authentication methods enabled on the Web server. Contact the Web server's administrator for additional assistance." I published the website(hosted on Azure) and on the site says: "You do not have permission to view this directory or page."