Reload PO Item before patch

erpnext/patches/v6_8/move_drop_ship_to_po_items.py

@@ -1,6 +1,7 @@
 import frappe
 
 def execute():
+	frappe.reload_doctype("Purchase Order Item")
 	for po in frappe.get_all("Purchase Order", filters={"delivered_by_supplier": 1}, fields=["name"]):
 		purchase_order = frappe.get_doc("Purchase Order", po)
 		
@@ -33,4 +34,4 @@ def update_per_billed(po):
 				where parent = %(name)s), 2) 
 			where name = %(name)s """, {"name": po.name})
 
-				
+