[minor] make-demo fixes for manufacturing domain (#10029)

diff --git a/erpnext/manufacturing/doctype/bom/bom.py b/erpnext/manufacturing/doctype/bom/bom.py
index ce895898..7130a3e 100644
--- a/erpnext/manufacturing/doctype/bom/bom.py
+++ b/erpnext/manufacturing/doctype/bom/bom.py
@@ -52,8 +52,8 @@
 		validate_uom_is_integer(self, "stock_uom", "stock_qty", "BOM Item")
 
 		self.update_stock_qty()
-		self.validate_materials()
 		self.set_bom_material_details()
+		self.validate_materials()
 		self.validate_operations()
 		self.calculate_cost()