This error is noticed in domains hosted in plesk servers. Nginx is running in frontend and Apache in the backend. This is mainly due to Apache doesn't reach the configurations added by Plesk.
* As a first step, we need to disable Nginx by using the following command
# /usr/local/psa/admin/bin/nginxmng -d
* Now the frontend web server is switched to apache. Check whether the issue still persists on the websites. If the issue is fixed. Enable Nginx again using the following command. This will resolve the issue.
# /usr/local/psa/admin/bin/nginxmng -e
* Make sure that zz010_psa_httpd.conf file is present in /etc/httpd/conf.d folder and also "IncludeOptional conf.d/*.conf" is addeded in apache conf (/etc/httpd/conf/httpd.conf)
* If the error for website is still not resolved after disabling Nginx, try rebuilding the Apache configuration files for the domain:
# /usr/local/psa/admin/bin/httpdmng --reconfigure-domain <domain_name>
or
# plesk repair web <domain_name>
* If the error is for all domains, please run following command
# /usr/local/psa/admin/bin/httpdmng --reconfigure-all
