diff --git a/addons/crm/models/crm_activity.py b/addons/crm/models/crm_activity.py
index 4be550c5564..e23d5cffdaf 100644
--- a/addons/crm/models/crm_activity.py
+++ b/addons/crm/models/crm_activity.py
@@ -43,8 +43,9 @@ class CrmActivity(models.Model):
 
     @api.multi
     def unlink(self):
-        activities = self.search([('subtype_id', '=', self.subtype_id.id)])
-        # to ensure that the subtype is only linked the current activity
-        if len(activities) == 1:
-            self.subtype_id.unlink()
+        for activity in self:
+            activities = self.search([('subtype_id', '=', activity.subtype_id.id)])
+            # to ensure that the subtype is only linked the current activity
+            if len(activities) == 1:
+                activity.subtype_id.unlink()
         return super(CrmActivity, self).unlink()
diff --git a/addons/point_of_sale/static/src/js/screens.js b/addons/point_of_sale/static/src/js/screens.js
index 4b6b142cac3..2d61f4b63a9 100644
--- a/addons/point_of_sale/static/src/js/screens.js
+++ b/addons/point_of_sale/static/src/js/screens.js
@@ -1985,6 +1985,7 @@ var PaymentScreenWidget = ScreenWidget.extend({
 
             invoiced.fail(function(error){
                 self.invoicing = false;
+                order.finalized = false;
                 if (error.message === 'Missing Customer') {
                     self.gui.show_popup('confirm',{
                         'title': _t('Please select the Customer'),