The web server fails to rebuild configuration and start due to the following error:
Unable to generate the web server configuration file on the host <plesk11.test> because of the following errors:
nginx: [emerg] listen() to 10.0.0.1:80, backlog 511 failed (98: Address already in use)
nginx: configuration file /etc/nginx/nginx.conf test failed
The problem is caused by a race condition in nginx init script (
/etc/init.d/nginx ), which causes the service start attempt to begin before all nginx worker processes are properly shut down.
This behavior was confirmed to be a software issue with ID # PPPM-353 .
This software issue has been fixed in Parallels Plesk 11.5.
Occasionally, the issue may resurface after an improper startup of Nginx, an operating system upgrade, or packages related to nginx. If it does, a restart of Nginx (with a slight delay between stop and start) will most likely help.