Normally, a browser requests (the contents of) a URL from a web server, and back comes an HTTP header saying "here you are", followed by a page of HTML (Or an image, or whatever). However, there is a feature of the HTTP protocol whereby the server can instead send back an HTTP header saying "look over there instead", which the browser then does. This is called redirection.

CRAITS uses redirection all over the place to navigate round the system, and won't work without it. Most fully-fledged browsers support it (including all the usual suspects) but some lightweight, "embedded" browsers do not.