Page Error

System.NullReferenceException: Object reference not set to an instance of an object.
   at Kidz.Business.External.frmRSVP.ProcessToken()
   at Kidz.Business.External.frmRSVP.OnPreInit(EventArgs e)
   at System.Web.UI.Page.PerformPreInit()
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)