Unable to apply PHP FPM settings: phpinimng failed: Unable to update the config file for 'fpm' service due to syntax errors

Symptoms

Note: this article can be applied in case of pm has a dynamic mode. 

• Unable to apply PHP-FPM settings in Plesk > Domains > example.com > PHP settings with the following error: 

  PLESK_ERROR: Error: phpinimng failed: Unable to update the config file for 'fpm' service due to syntax errors.

• pm has a dynamic status.

  

Cause

Incorrect combination of values for below FPM settings:

• pm.start_servers
• pm.min_spare_server
• pm.max_spare_servers

Resolution

Set the values for PHP FPM settings according to the following rules:

• pm.min_spare_servers and pm.max_spare_servers cannot be greater than pm.max_children.
• pm.min_spare_servers must be less then pm.max_spare_servers.
• pm.start_servers must be greater than pm.min_spare_servers and not greater than pm.max_spare_servers.

Additional information:

PHP-FPM configuration files for subdomains or additional domains are not deleted

Unable to create the domain: Unable to update the config file for 'fpm' service due to syntax errors