Nothing changed using the original link. WordPress is still saying unauthorised.
Wordpress is presumably finding either a file or a folder at https :// nakedexperiment.com/age-verified/whats-the-problem-with-nudity/ otherwise it would say not found rather than unauthorised.
Most of the age verified videos are hosted on vimeo rather than here. Are there any other videos in https :// nakedexperiment.com/age-verified/ which are currently working?