Hello everybody! I recently have been discovering Nginx (coming from a all-in Apache user). Today was my first dive with ISPConfig + Nginx + PHP-FPM. My problem was that after a successful installation rutine, ISPConfig's trigger to initiate the site's .vhost file failed. I kept seeing error messages in the log like: Code: WARNING - nginx did not restart after the configuration change for website DOMAIN_NAME Reverting the configuration. Saved non-working config as /etc/nginx/sites-available/DOMAIN_NAME.vhost.err ...and... Code: DEBUG - chmod failed: /var/www/clients/client#/web#/web/stats/.htpasswd_stats : 493 After tons of Googling, I found the solution to actually be to increase nginx's server_names_hash_bucket_size I am posting this to help any future Googler find it X minutes faster than I did and support the community!