How do I configure the "input format" for the File Tree module?
If you want to get File Tree to work, after you set up the input filter, the directory you are referring in [filetree dir="dirname"] must be a directory contained in your site's "files" directory. If you want to display all the files in the "files" directory use [filetree dir="/"], or if you want to display a particular directory, put the files in a directory (say, dir1) under files and specify [filetree dir="/dir1"].