Error "Template lacks the section required for the module to work"

Symptoms

When attempting to enable any option in the site settings, an error stating that a section required for module operation is missing from the configuration file appears.

The following error is registered in the Panel log /usr/local/mgr5/var/ispmgr.log:

ERROR Error: Type: 'web' Object: 'missing_section' Value: '$PHPCOMPOSER'

Causes

A custom configuration file template for sites is being used. The configuration file template is missing variables and sections required for the module to work.
 

Solution

Update custom templates of configuration files at /usr/local/mgr5/etc/templates/.

Standard valid templates are located at /usr/local/mgr5/etc/templates/default/.