After importing Service Plan/Add-On plan to a new server, the Service Plans > <service_plan/add-on_plan name> page can not be opened in Plesk with:
Argument 1 passed to Service_Node_Environment_PhpHandlers_Abstract::isFpmDedicatedHandler() must be of the type array, null given, called in P:Program Files (x86)PleskadminplibCommonPanelFormPhpSettingsWithPhpHandler.php on line 176
Importing a service plan with a PHP handler that is not available on a target server breaks Plesk functionality.
The bug with ID PPPM-13346 was created to address this behavior so Plesk can render the page with the Service Plan settings for editing even if the PHP handler is broken.
Connect to the server via RDP.
Run the command below to register PHP handlers on a new server:
C:> plesk repair web -y