Sales Order line delete error: This line has offsetting issues and returns, and cannot be deleted
The Sales Orders screen will prevent deleting of any line that has had transactions against it (even if the transaction was a pick and then a reversal of that pick). The line has to be preserved for a historical audit trail.
Our recommendation, if this line is no longer needed, is to set its Qty to 0 in the 'Details' tab of the Sales Order. The line will still show up on the Acknowledgement but it will have a 0 qty beside it. The Packing List will not have the line if the line isn't included in the shipment and, subsequently, it won't show up on the Invoice because it wasn't included on the shipment.