SkinnableTextBase focusManager runtime error popup

roustalski writes somthing that will save you quite a bit of time if you get caught with this runtime error; When you show a popup in Flex in a mobile environment, defined as the style “interactionMode” being set to InteractionMode.TOUCH in this context, that is based on a component that does not implement the mx.managers.IFocusManagerContainer interface, you will receive a runtime error when the user taps the control that is to receive focus.

via Flex 4 Examples.