Subscription is not synchronized in Plesk: some of the services or resources defined in the plan cannot be actually provisioned

Symptoms

Synchronization of subscription is not performed with the following error in Plesk:

PLESK_ERROR: Syncing the subscription with its service plan failed because some of the services or resources defined in the plan cannot be actually provisioned with the subscription. Available value indicates the actual state of a resource or a service in the system. Clicking OK will initiate setting the subscription values according to the available values.

Cause

Required limits in subscription's settings are not met with the Service Plan. Therefore, subscription is customized and is locked from synchronizing.

Resolution

Log in to Plesk and apply any of the following solutions:

• Reduce subscriptions limits to meet with the service plan: Subscriptions > example.com > Customize
• Re-assign the subscription to a different plan that has more resources: Subscriptions > example.com > Change Plan
• Keep subscription unsynced (locked)

For example, if the number of mailboxes for a subscription exceeds the value defined in the service plan, reduce the number of mailboxes in Subscriptions > example.com > Email Addresses or set bigger amount of allowed mailboxes in Service Plans > Mailboxes.