- Plesk for Windows
PHP Settings button is available while no PHP handlers installed on a server and proper settings in service plan applied. This results in an error about missing handler:
Domain "example.com": the PHP handler "fastcgi-5.6" is not registered
Resources and permissions for the subscription cannot be customized with the same error as above
This is Plesk bug with ID #PPPM-6125 which is planned to be fixed in future Plesk updates.
As a workaround, replace the following files with the attached ones:
Create backups of the originals files first.
If it is not possible to create a subdomain when there are no PHP handlers installed, check the article: Cannot create subdomain: there are no available PHP handlers