diff --git a/product/ERP5/Document/SubscriptionItem.py b/product/ERP5/Document/SubscriptionItem.py
index f84364cc70f9f39f7156fb4d156f460113144f1d..fccd4a780615da701471fd11b9a3ac48db2a788f 100644
--- a/product/ERP5/Document/SubscriptionItem.py
+++ b/product/ERP5/Document/SubscriptionItem.py
@@ -281,6 +281,9 @@ class SubscriptionItem(Item, CompositionMixin, MovementGeneratorMixin, Periodici
         resource = movement.getResource()
         start_date = movement.getStartDate()
         stop_date = movement.getStopDate()
+        if start_date is None or stop_date is None or start_date>stop_date:
+          # infinity nor time back machine does not exist
+          continue
         source = movement.getSource()
         source_section = movement.getSourceSection()
         source_decision = movement.getSourceDecision()