Module::DelegationError (Spree::Order#invoice_number delegated to invoice.number, but invoice is nil

[ewenjc]

Hi
I'm getting the following error each time I attempt to add an item to the cart; "Module::DelegationError (Spree::Order#invoice_number delegated to invoice.number, but invoice is nil", while running `ensure_cart'.

I have a clean install of spree 4.1. However I've imported order data from a spree 2.4 implementation, so possibly that is causing the issue. Within order I still have the invoice_number and invoice_date.

EDIT:
Error message solved
The error was caused by still having the invoice_number field on orders. I renamed the columns invoice_number and invoice date and the error went away.

Data migration still a problem
I tried to migrate the invoice numbers from the old 2.4 setup into the new spree 4.1 setup. I added the following migration;

`class RenameInvoiceNumberOnOrder < ActiveRecord::Migration[6.0]
def change
up_only {
Spree::Order.complete.where.not(invoice_number: nil).find_each do |order|
order.bookkeeping_documents.delete_all
order.invoice_for_order
order.invoice.update(number: order.invoice_number, created_at: order.completed_at.to_date)
order.packaging_slip.update(number: order.invoice_number, created_at: order.completed_at.to_date)
end
}
rename_column :spree_orders, :invoice_number, :old_invoice_number
rename_column :spree_orders, :invoice_date, :old_invoice_date
end

end
`

It recreated the invoices but the invoice numbers didn't set as the old numbers. The order numbers didn't set to the old number but a number a few thousand higher. Possibly it is taking the next invoice number and adding the old number to it?
Also attempting to set the number on the packaging_slip to the old invoice number had no effect and it kept the packaging slip number as the order number.