Github user alopresto commented on the issue:
https://github.com/apache/nifi/pull/2759
I think the issue is that the link from that menu goes to
`http://localhost:8080/nifi-docs/documentation` when the correct URL is
`http://localhost:8080/nifi-docs/html/overview.html`. If that URL is entered
manually, the correct resources are served to the browser. ---
