You get an error when you open an MXML or ActionScript file by right-clicking the file, selecting Open With, and browsing to the Flash Builder executable.
Note: The error occurs only for the standalone configuration of Flash Builder, and if you have not selected Flash Builder as the default application to open MXML and ActionScript files.
Select Flash Builder as the default application to open MXML and ActionScript files by following these steps:
Open the Preferences dialog, and select Flash Builder > File Associations.
Select ActionScript Files (*.as) and MXML Files (*.mxml) to set the file associations.
Note: Specifying a file association overrides operating system settings.
MXML file, ActionScript file, fail, error, open, Flash Builder; cpsid_89947