Custom widget tutorial pages do not work anymore

I start at the documentation dashboard, then click tutorials. ( This works. When I select Custom Widgets ( the page is displayed but shows errors about an unknown macro. Any of the subpages do not work at all, including the widget XML reference.
1 answers

It is very frustrating that the pages do not work. I'm trying to build my own widget but I can not rely on some examples alone as the widget creation process is not that intuitive.