My gp has two inputs that are two features. One is a selected of a feature layer and the other is all features of the same feature layer. A similar gp works fine in javascript but I get an error in Flex. Can anybody tell me how to get the parameters from a feature layer? ThanksThis is the error I got when I select the feature and then click the button to run the gp:[RPC Fault faultString="Error performing execute operation" faultCode="500" faultDetail="" private function calculalteplanind():void { var SelectingFeature:FeatureSet = new FeatureSet(); SelectingFeature.features = myFeatureLayerstewardship.selectedFeatures var features:ArrayCollection = ArrayCollection(myFeatureLayerstewardship.graphicProvider); var featureSet:FeatureSet = new FeatureSet(features.source); Alert.show ("GP RUNNING") var params:Object = { "Selecting_Features": SelectingFeature, "Stewardship": featureSet } gp.execute(params, new AsyncResponder( onResult, onFault )); function onResult(gpResult:ExecuteResult = null, token:Object = null):void { Alert.show("YAY") } function onFault(info:Object, token:Object = null):void { Alert.show(info.toString()); } } <esri:Geoprocessor id="gp" useAMF="false" outSpatialReference="{myMap.spatialReference}" processSpatialReference="{myMap.spatialReference}" url="http://tfsgis-iisd01:6080/arcgis/rest/services/TwoParametersWithSelection2/GPServer/CalcFeaturesStewardshipOneParameterSelection" />