Fix problem with modifying orders

src/pretix/presale/views/order.py

@@ -363,6 +363,9 @@ class OrderInvoiceCreate(EventViewMixin, OrderDetailMixin, View):
 class OrderModify(EventViewMixin, OrderDetailMixin, QuestionsViewMixin, TemplateView):
     template_name = "pretixpresale/event/order_modify.html"
 
+    def _positions_for_questions(self):
+        return self.positions
+
     @cached_property
     def positions(self):
         return list(self.order.positions.order_by(

src/pretix/presale/views/questions.py

@@ -7,6 +7,10 @@ from pretix.presale.views import get_cart
 
 
 class QuestionsViewMixin:
+
+    def _positions_for_questions(self):
+        return get_cart(self.request)
+
     @cached_property
     def forms(self):
         """
@@ -15,7 +19,7 @@ class QuestionsViewMixin:
         submitted at once.
         """
         formlist = []
-        for cr in get_cart(self.request):
+        for cr in self._positions_for_questions():
             cartpos = cr if isinstance(cr, CartPosition) else None
             orderpos = cr if isinstance(cr, OrderPosition) else None
             form = QuestionsForm(event=self.request.event,