Subscription with Billing Model "Charge After Billing Period" is canceled and has status "Terminated". Its service was not removed but when trying to restore this subscription an error is showed:
cast to numeric type on NULL value
Canceled but not removed subscriptions with Billing Model "Charge After Billing Period" cannot be restored because of software-related issue #PBA-65950.
This issue was fixed in Business Automation 6.0 Update 8. Contact your Technical Account Manager or Pooled Technical Associate Team at firstname.lastname@example.org in order to clarify the possibility of update installation.