It looks like there's a bad redirect when vising the website from the main homepage of https://logging.apache.org/. When I click on it, I go to https://logging.apache.org/log4cxx which then goes to https://logging.apache.org/log4cxx/latest_stable/latest_stable/, which gives me a 404.
I'm able to go to the website directly if I change it to go to index.html instead: https://logging.apache.org/log4cxx/latest_stable/index.html -Robert Middleton