I started a new Flex 4 project in Flash Builder 4 and it is relatively clean - just MXML and AS files. There are two swcs. One with embedded fonts and the other with a preloader animation. It uses Parsley and the Parsley config file <Objects> gets rejected. So I excluded that.
The error I get is:
Error: unable to open 'Flash'
Use 'asdoc -help' for information about using the command line.