diff -r e098ffef0317 sale.py
--- a/trytond/trytond/modules/sale_shipment_grouping/sale.py	Sat Feb 21 09:21:21 2015 +0100
+++ b/trytond/trytond/modules/sale_shipment_grouping/sale.py	Tue Feb 16 10:43:38 2016 +0100
@@ -37,6 +37,8 @@
         defaults = Shipment.default_get(self._shipment_grouping_fields,
             with_rec_name=False)
         for field in self._shipment_grouping_fields:
+            if not hasattr(shipment, field):
+                continue
             shipment_domain.append((field, '=',
                     getattr(shipment, field, defaults.get(field))))
         return shipment_domain