We have an advanced build process where our projects are build on a windows server and this includes updating the version in each SWF compiled. This is done by replacing a string in a file which is included in the main actionscript file of the project. The include self is not the problem but parsing the file that's being included causes the problems. The file (version.inc.as) only contains the following line: public static const VERSION:String = "@VERSION@"; The parser cannot parse this file and wrapping the line in /FDT_IGNORE/ tags does not work. So I'd like to ignore this file completely. A change in a configuration file of the project will do. We're currently trying FDT5 for 30 days, we had no problems with this using Adobe Flash Builder 4.6.