One or several tasks "Subscription update" are marked as failed in Plesk Multi Server task list with the following error message:
PLESK_ERROR: Failed API request: Parser error: Request is invalid. Error in line 3: Element 'id': '0' is not a valid value of the atomic type 'id_type'.
This behavior is confirmed as bug EXTPMS-1365: "Element 'id': '0' is not a valid value of the atomic type 'id_type'" error on Subscription update task.
This error message does not affect the correct work of Plesk and can be safely ignored.