After upgrade to POA 5.5, APS unprovisioning tasks are failing with an error message similar to this:
Foreign key 'aps_service_instance_resources_fk0' violation while executing ' DELETE FROM aps_service_instances WHERE service_instance_id = ?'.
Product issue fixed in POA 5.5 update 1.
Install POA 5.5 update 1 as soon as it is available and resubmit the failed task.