Loading configuration file C:\Program Files\Adobe\Adobe Flash Builder 4\sdks\3.5.0\frameworks\flex-config.xml
Version 3.5.0 build 12683
Copyright (c) 2004-2007 Adobe Systems, Inc. All rights reserved.
Error: ” is not a directory
Use ‘asdoc -help’ for information about using the command line.
This is happening because the asdocs folder, and more importantly asdocs/templates folder wasn't included in the 3.5 distribution of the Flex SDK. Simply copy asdocs from 3.4 or another 3.x sdk and it'll work.