Whitelabel Error Page

[Jose-Luis]

Following the tutorial using the web generator, when try to render HtmlController give this error:
"Whitelabel Error Page

This application has no explicit mapping for /error, so you are seeing this as a fallback.
Wed Nov 28 11:52:51 CET 2018
There was an unexpected error (type=Not Found, status=404).
No message available"
the problem seems to be the lack of @ResponseBody annotation on demo method (At least work for me)

[Jose-Luis]

I miss understand the tutorial, sorry