If you try to localize a flex application with e.g. en_US and de_DE locales, FlexBuilder will likely complain about a missing german framework resource:

unable to open ‘/Applications/Adobe Flex Builder 3 Plug-in/sdks/3.2./…’

No need to give up, make the resource yourself:

- Open the SDK’s root folder. On a Mac, it is likely to be here:

/Applications/Adobe Flex Builder 3 Plug-in/skds/3.2

- Execute this command

./bin/copylocale en_US de_DE

Now recompile - probably clean it before - your project your Flex project. Everything should look fine.