Just in case you, like another one of my clients, wants to use this ProcessFlow Service to notify the Agreement Administrator that the PO's released against a Vendor Agreement have exceeded the notification percent on the PO25 setup form - you will need to make sure that ProcessFlow Administration (menu.do) has the Form and Form Field Definitions defined for the PO25.1 form.
For some reason, like for the Invoice Approval AP26.1 form, this form definition is missing and this Service won't work without it.