Change Flash Builder 4.7 language on mac

1. Exit FB and open the finder and go to the Flash Builder install directory

2. Right click on Adobe Flash Builder 4.7.app and select “Show Package contents”

3. Navigate to Contents/MacOS

4. Edit Adobe Flash Builder 4.7.ini in TextEdit

5. Change the -nl to en_US

-nl
fr_FR

Becomes

-nl
en_US

6. Save the file and launch FB

Source :
http://forums.adobe.com/thread/448441