Replace all the NULL values with zeros in the feature service.Modify chart's preview.js. after the call on line 1906//filter features with number values firstly var fs = args.featureSet.features;and add the following:array.forEach(fs, lang.hitch(this, function(feature) { var attributes = feature.attributes; array.forEach(valueFields, lang.hitch(this, function(fieldName) { if (attributes[fieldName] === null && typeof attributes[fieldName] === "object") attributes[fieldName] = 0; })); }));