Thank you for your kindly reply Mr. Yang. It's my fault from the installation phase of LCDS, I use theJ2EE server choice instead of JRUN. So when I start the new Flex& LCDS Project and when I typed <mx:DataService> ineditor the error will wait for me.When I reinstall with integrated JRUN option it w...

I have the same problem to you too. I look into the Flex 3Language Reference and found the mx.data.DataService was gone and Idon't understand why adobe do that. Now I have a question "If Ican't invoke <mx:DataService>, how can I use data managementservice of LiveCycle Data Service ES? and another qu...