When reseller customized service plan of reseller and performed "sync", it is going to be failed and following error messages appeared.
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.
The issue could be caused by difference between the customized parameters of the subscription and its Service Plan. In common case, you need to check permissions and limitations defined in Resellers Service Plan or reseller account settings defined by Plesk administrator.
Login in Plesk as administrator and check settings for required reseller account, set correct value and apply changes.
Try to synchronize required subscription under reseller account.
Note: You can find additional information about syncing resellers Subscriptions and Service Plans in Reseller's Guide .