I found this bug trying to set up my own edit widget. Decided to double check in the default viewer to make sure I wasn't doing something wrong. Got the same result. Apologies in advance, this should probably be in the api forum.
1. Open Edit Widget 2. Check "San Francisco 3-1-1 Incidents" 3. Click feature on map to open inspector 4. Edit any attribute 5. Click Ok 6. Click Undo and receive the following error:
TypeError: Error #1009: Cannot access a property or method of a null object reference. at com.esri.ags.components::AttributeInspector/validate() at com.esri.ags.components::AttributeInspector/set activeFeatureIndex$() at com.esri.ags.components::AttributeInspector/set activeFeatureIndex() at com.esri.ags.components::AttributeInspector/refresh() at com.esri.ags.components.supportClasses::EditAttributesOperation/undoattributeInspector_editsCompleteHandler() at mx.rpc::AsyncResponder/result() at com.esri.ags.tasks::FeatureLayerTask/handleApplyEdits() at Function/http://adobe.com/AS3/2006/builtin::call() at com.esri.ags.tasks::BaseTask/handleResultEvent() at mx.rpc::AsyncResponder/result() at mx.rpc::AsyncToken/http://www.adobe.com/2006/flex/mx/internal::applyResult() at mx.rpc.events::ResultEvent/http://www.adobe.com/2006/flex/mx/internal::callTokenResponders() at HTTPOperation/http://www.adobe.com/2006/flex/mx/internal::dispatchRpcEvent() at mx.rpc::AbstractInvoker/http://www.adobe.com/2006/flex/mx/internal::resultHandler() at mx.rpc::Responder/result() at mx.rpc::AsyncRequest/acknowledge() at DirectHTTPMessageResponder/completeHandler() at flash.events::EventDispatcher/dispatchEventFunction() at flash.events::EventDispatcher/dispatchEvent() at flash.net::URLLoader/onComplete()
Version 3.5 was released today and includes the fix for this issue: * Runtime error when performing an "undo" during editing. Bug was specific to version 3.4.
