featdd

	/**
	 * A special action which is called if the originally intended action could
	 * not be called, for example if the arguments were not valid.
	 *
	 * The default implementation sets a flash message, request errors and forwards back
	 * to the originating action. This is suitable for most actions dealing with form input.
	 *
	 * We clear the page cache by default on an error as well, as we need to make sure the
	 * data is re-evaluated when the user changes something.
	 *