Displays error pages. All pages must be plain HTML. No templating engine can be used. The pages must be named
In multi language sites the localized version of the error page can be saved in
templates/<locale_name>/<page_name>. If the file does not exist or if the site is single language then the location
templates/<locale_name>/<page_name> is checked. If the error page still can not be found a global one will be used.