My regex works when doing things like foo/bar and one with spaces/two with spaces/three with spaces/four with spaces etc, but it directs to the 404 page when using urlencode in PHP.
The following test shows that encoded strings don't work in the URL: http://regex101.com/r/jP0gW1
Anyone have any ideas? It also breaks when using the "+" character.
That's because you were not handling the % in your regex. \w only matches alphanumerical characters.
Adding a % to your regex made it work:
^([\w\ ]+)(?:/([\w\ ]+))?(?:/([\w\% ]+))?(?:/([\w\ ]+))?(?:/([\w\ ]+))?(?:/([\w\ ]+))?/?$
You can simplify your regex if you want to:
/^([\w\s%]+\/).*$/