Compiler error with selectedChild in Flex 4 with code that worked in Flex 3 - Flex Butterflies and Bugs

Compiler error with selectedChild in Flex 4 with code that worked in Flex 3 - Flex Butterflies and Bugs: "Compiler error with selectedChild in Flex 4 with code that worked in Flex 3

A customer filed a bug recently about a backwards compatibility issue that they ran into when trying to compile their Flex 3 application in Flex 4. Normally, your application should compile just fine, but, you might run into some behavioral differences between the two releases.

However, in the case described in bug SDK-25021, your application won’t even compile! When using the ’selectedChild’ property for any of the MX Navigators like TabNavigator, ViewStack or Accordion, you will get the following error in Flex 4:"