If the geoprocessing functionality is not initialized, the application will return an error "object reference not set to an instance of an object". In the Default.aspx.cs, the beginning of the CalculateBufferServer method should be as follows: IGeoprocessingResource igp = GeoprocessingResourceManager1.GetResource(0); ESRI.ArcGIS.ADF.Web.DataSources.ArcGISServer.GeoprocessingFunctionality agp = (ESRI.ArcGIS.ADF.Web.DataSources.ArcGISServer.GeoprocessingFunctionality) igp.CreateFunctionality(typeof(ESRI.ArcGIS.ADF.Web.DataSources.IGeoprocessingFunctionality), null); agp.Initialize();