Web Adapter Config web page error

Discussion created by StephenTWong on Sep 19, 2012
I installed Web Adapter on a machine and tried to run the Web Adapter Configuration and got the error from the web page:

[NullReferenceException: Object reference not set to an instance of an object.]
   ESRI.ArcGIS.WebAdaptor.Config.SetupUI() +680
   ESRI.ArcGIS.WebAdaptor.Config.Page_Load(Object sender, EventArgs e) +55
   System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +14
   System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +35
   System.Web.UI.Control.OnLoad(EventArgs e) +99
   System.Web.UI.Control.LoadRecursive() +50
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +627

  Anyone know how to resolve it?