using: ver 21.4.87 win10 desktop, I played with this new feature.
the following workflow results in an internal error
created sales order with inventory item qty is 10
and Track quantity to deliver is checked
copy to new Delivery Note
copy Delivery Note to New Sales Invoice
Customer returns 1 Item
copy Sales Invoice to New Credit Note
created Delivery Note with a negative qty to record the return
recorded a payment from bank account and allocated the refund to Accounts receivables
this procedure returns a Qty to deliver of 1 to the Qty to deliver column in the Sales Orders Summary
clicking on the pending Qty in the Sales Order Overview and on the Qty to deliver in the next window Sales Order XXX — Qty to deliver, will result in this Internal Error.
clicking on Go back and Back will bring you back to the Sales Orders Summary
Adjusting the Qty to 9 in the Sales Order will show a zero ( 0 ) for the Qty to deliver in the Summary
Is it supposed to work this way ?