Pycharm Type Renderer not working

I followed the documentation for Type Renderer: https://www.jetbrains.com/help/pycharm/customizing-views.html#renderers

But it seems that it is not working. I get a “Class not found” popup when I type the qualified name of the class that I want to type render even though the class is shown in the list as I am typing its name. The type renderer for builtin objects like List for example is working, however. Any help?