On Windows Small Business Server 2011 Standard/Essentials, you may get the following error when you browse Remote Web Access (RWA) web site.
HTTP Error 401.2 - Unauthorized You are not authorized to view this page due to invalid authentication headers.
This issue can occur if Anonymous Authentication has been disabled on Remote application in IIS.
To resolve this issue, follow these steps:
Open IIS Manager.
Navigate to Server Name -> Sites -> Default Web Site -> Remote.
Select Remote and then double-click Authentication from Features View pane.
Select Anonymous Authentication and click Enable from Actions pane.
Run IISRESET /noforce.
Note: The same steps are applicable if you face this issue on Small Business Server 2008 Standard with Remote Web Workplace (RWW).