umbraco tried this to match it using this xpath query'/root/*/* [@urlName = "forum"]/* [@urlName = "default"] | /root/* [@urlName = "default"]')
This page can be replaced with a custom 404 page by adding the id of the umbraco document to show as 404 page in the /config/umbracoSettings.config file. Just add the id to the '/settings/content/errors/error404' element.
For more information, visit information about custom 404 on the umbraco website.
This page is intentionally left ugly ;-)