see documentation on "Authorization Issue: ArcGIS Spatial Data Server for IIS 10.1 Beta 1" on the Beta Community: <a href="https://betacommunity.esri.com/project/article/item.html?cap=B33ECCA27C1A464F8A2936EBBA54BB70&artid=" target="_blank">https://betacommunity.esri.com/project/article/item.html?cap=B33ECCA27C1A464F8A2936EBBA54BB70&artid=</a>{A68B8129-7B9C-4062-A4B6-89DAB61F16E5