"Sales document was in use and couldn't be updated. Please perform the sales reconcile to update quantities and/or costs."

Hi! We have Drop-Ship Purchase Orders committed to sales order. We have fully received the items in PO but when trying to transfer the sales order committed to that purchase order, we CANNOT transfer  the SALES ORDER to INVOICE. We got "0 Error(s) during transfer"  "0 Document(s) transferred successfully" in SOP Transfer Log.

I tried to run the script: select QUANTITY, QTYORDER, QTYPRINV, * from SOP10200 where SOPNUMBE = 'XXX'

**Where XXX is the SOP Order document number.

This gave me the results:

A.) Sales Order 1

Qty:      QtyOrder     QtyPrinv

2              0                   0 

2              0                   0

6              0                   0

2              0                   0

B.) Sales Order 2

Qty         QtyOrder     QtyPrinv

1                0                 0

1                0                 0

But haven't try yet to reconcile sales document.

What could be done and what is the reason behind this?

Thanks in advance!