HTTP Error 401.2 – Unauthorized. You are not authorized to view this page due to invalid authentication headers.
This is due to IIS configuration not configured on the Windows 2008 server.
Go to IIS,
Click Enable on the Actions pane for Forms Authentication and Windows Authentication.
You can ignore the error or warning you will get saying “ Challenge based and login-redirect authentication cannot be used simultaneously”
Hopefully this resolves this error. Let us know if you have any queries.