diff --git a/SAS/TMSS/src/tmss/tmssapp/serializers/specification.py b/SAS/TMSS/src/tmss/tmssapp/serializers/specification.py
index abe99626f95bdc6baa6af6a17383b4532ea3042f..9cfe925f96aec9c94715c33c6637499433f1bc38 100644
--- a/SAS/TMSS/src/tmss/tmssapp/serializers/specification.py
+++ b/SAS/TMSS/src/tmss/tmssapp/serializers/specification.py
@@ -16,7 +16,10 @@ class RelationalHyperlinkedModelSerializer(serializers.HyperlinkedModelSerialize
 
     def get_field_names(self, declared_fields, info):
         field_names = super().get_field_names(declared_fields, info)
-        field_names.remove(self.url_field_name) # is added later, see retun statement
+        try:
+            field_names.remove(self.url_field_name) # is added later, see retun statement
+        except ValueError:
+            pass
 
         if getattr(self.Meta, 'extra_fields', None):
             field_names += self.Meta.extra_fields
diff --git a/SAS/TMSS/src/tmss/tmssapp/tasks.py b/SAS/TMSS/src/tmss/tmssapp/tasks.py
index 70642135c4f666f25f115aed23b08413ccddaa5a..b143f3e0646d91bc16006bcdb0751c936a32f2d4 100644
--- a/SAS/TMSS/src/tmss/tmssapp/tasks.py
+++ b/SAS/TMSS/src/tmss/tmssapp/tasks.py
@@ -49,8 +49,11 @@ def copy_scheduling_unit_draft(scheduling_unit_draft: models.SchedulingUnitDraft
 
     scheduling_unit_draft_copy.scheduling_set=scheduling_set_dst
 
+    task_drafts_copy = []
     scheduling_unit_draft_copy.save()
-    scheduling_unit_draft_copy.task_drafts.set(task_drafts)
+    for td in task_drafts:
+        task_drafts_copy.append(copy_task_draft(td))
+    scheduling_unit_draft_copy.task_drafts.set(task_drafts_copy)
     scheduling_unit_draft_copy.scheduling_unit_blueprints.set(scheduling_unit_blueprints)
     scheduling_unit_draft_copy.save()