When I pass cassini a path, using the configuration api, of "c:\program files\mydir\\mywebapp", cassini crashes if I try to access my app. If I use your management interface and edit the properties, then my app runs fine and cassini doesn't crash. My app reads a path specified by the user and then appends "\mywebapp" to it. It works fine with everything else within my app except cassini. I have modified my configuration UI to catch this, but I just wanted to give you a heads up.