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

 Error message 401.2.: 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

https://www.c-sharpcorner.com/blogs/error-message-4012-unauthorized-logon-failed-due-to-server-config