Fixed bug with new defualt permissions.

gracedb/permission_utils.py

@@ -52,7 +52,7 @@ def assign_default_event_perms(event):
         assign_perm(change_codename, g, event)
 
     # If the event is an MDC event, then we expose it to LV-EM also
-    if event.search.name == 'MDC':
+    if event.search and event.search.name == 'MDC':
         lvem = Group.objects.get(name='gw-astronomy:LV-EM')
         assign_perm(view_codename, lvem, event)
         assign_perm(change_codename, lvem, event)