I'm building an Flex 4 application using IntelliJ IDEA generated sample Flex application. I replace the mxml with the following code from the book Hello Flex 4. It simply crashes the browser when I run it. I tried it on both FF and Chrome. Any clues? [Bindable] public var _bread:Number = Number.NaN; ]]></fx:Script> <fx:Declarations> <s:RadioButtonGroup id="moralityRBG"/> <s:RadioButtonGroup id="restaurantRBG" selectedValue="{_theory.length % 2 == 0 ? 'smoking' : 'non'}"/> </fx:Declarations> <s:Panel width="100%" height="100%" title="Simple Components!"> <s:layout> <s:HorizontalLayout paddingLeft="5" paddingTop="5"/> </s:layout> <s:VGroup> <s:TextArea id="textArea" width="200" height="50" text="@{_theory}"/> <s:TextInput id="textInput" width="200" text="@{_theory}"/> <s:HSlider id="hSlider" minimum="0" maximum="11" liveDragging="true" width="200" value="@{_bread}"/> <s:VSlider id="vSlider" minimum="0" maximum="11" liveDragging="true" height="50" value="@{_bread}"/> <s:Button label="{_theory}" width="200" color="{alarmTB.selected ? 0xFF0000 : 0}" click="_bread = Math.min(_theory.length, 11)"/> <s:CheckBox id="checkBox" selected="{_bread % 2 == 0}" label="even?"/> </s:VGroup> <s:VGroup> <s:RadioButton label="Good" value="good" group="{moralityRBG}"/> <s:RadioButton label="Evil" value="evil" group="{moralityRBG}"/> <s:RadioButton label="Beyond" value="beyond" group="{moralityRBG}"/> <s:RadioButton label="Smoking" value="smoking" group="{restaurantRBG}"/> <s:RadioButton label="Non-Smoking" value="non" group="{restaurantRBG}"/> <s:ToggleButton id="alarmTB" label="ALARM!"/> <s:NumericStepper id="numericStepper" value="@{_bread}" minimum="0" maximum="11" stepSize="1"/> <s:Spinner id="spinner" value="@{_bread}" minimum="0" maximum="11" stepSize="1"/> </s:VGroup> </s:Panel>