diff --git a/sync/views.py b/sync/views.py
index ceb9870..b1caf34 100644
--- a/sync/views.py
+++ b/sync/views.py
@@ -109,6 +109,7 @@ class SynchronizationApi(HierarchyApiView):
                 instance._device_id = device_id
                 return Response(serializer.data, status=status.HTTP_201_CREATED)
             else:
+                print(f'Data invalid ! {serializer.errors}')
                 return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
         elif model_operation == 'PUT':
             data_id = data.get('id')
@@ -124,6 +125,7 @@ class SynchronizationApi(HierarchyApiView):
                     print('>>> return 203')
                     return Response(serializer.data, status=status.HTTP_203_NON_AUTHORITATIVE_INFORMATION)
             else:
+                print(f'Data invalid ! {serializer.errors}')
                 return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
         elif model_operation == 'DELETE':
             data_id = data.get('id')