From FDT Documentation

FDT provides some Ant tasks of its own. To assure that these tasks work, the task has to run in the same JRE (Java Runtime Environment) as Eclipse.

JRE - A Common Pitfall

Before getting into Ant, an important concept to understand is how Ant tools, by default, run in their own JRE.

This bit needs a If you get the message "BUILD FAILED Could not create task or type ..." your task probably runs in another JRE. This can be corrected. Therefore got to "Run- >External Tools->External Tools..." in the main menu. Choose your run configuration and go to the tab "JRE". Change the option "Runtime JRE" from "Separate JRE" to "Run in the same JRE as the workspace".

Tasks

fdt.flashCompile

This task compiles a single FLA or a set of FLA's with the Flash IDE. The Flash IDE must be set in the Flash Preferences (see "Preparing the workbench (AS2)"). The Flash Output is captured and shown in the console. If any error occurs the build will be aborted. You can define a timeout for how long the build waits for the output. If the timeout is not specified the task will take a 60 second timeout. Syntax: <fdt.flashCompile file="fla" timeout="t in ms " /> Arguments: 1. file : the FLA to compile 2. timeout : the timeout(ms) for how long the tasks wait until it fails