[exec] Loading configuration file D:\Program Files\Adobe\Flex Builder 3 Plug-in\sdks\3.2.0\frameworks\flex-config.xml
[exec] Error: could not find source for class org.igniterealtime.xiff.logging:TextAreaTarget in namespace http://www.igniterealtime.org/projects/xiff.
[exec] Result: 1
Total time: 657 milliseconds
Currently the manifest file is outdated for the build.
The build file itself is a bit outdated and I have added a new issue to update it: XIFF-62.
Patch is posted:
Updated ant build files have been committed.