D8 file_private_path not working

I am setting up my Drupal site builder environment. I get a warning that I need to setup the private file system in settings.php. So I created a director /var/www_data/private. I put a .htaccess file in the directory as described at https://www.drupal.org/SA-CORE-2013-003 I chown to www-data:www-data on the directory and the .htaccess file. I chmod 740 on the directory. I chmod 444 on .htaccess. Now I am still getting the same warning, but I am getting an error saying the directory is not properly secured.

Any ideas what I should do next?


Drupal version: 

Source: https://www.drupal.org/taxonomy/term/22/feed