This file browsing servlet requires RDS to function. The RDS servlet is disabled by default. It should be disabled on a production server, but if you’d like to use this feature you’ll need to un-comment the servlet call in your server’s web.xml.
In my case this file was located at F:\JRun4\servers\cfusion\cfusion-ear\cfusion-war\WEB-INF\web.xml but I’m running multiserver. Your’s could be under your CF9 install directory if you’re running CF as a standard install.
Un-comment these two servlet definition blocks in web.xml.
Now restart your CF server instance and navigate back to the administration page you were wanting to use.