How do you cancelled a “Delivered” Sales Status? When you try to delete it, you get the following message: Order line must be invoiced first.
Post the packing slip by having negative quantity in the delivery now.
When you have delivered something why do you want to delete it? Invoice it and delete it or process a negative deliver now and then delete the open order.
I don’t think you can delete any order with posted transactions linked to it? Cancel it and that should be ok after you have done a de-receipt.
You can invoice it then delete it depending upon your control on invoiced orders, but the transactions remain. Makes no sense to invoice it when you want to “delete” it however.