diff -r 9428a143e925 -r 40d8113560e4 src/hdalab/views/ajax.py
--- a/src/hdalab/views/ajax.py	Tue Mar 31 02:03:42 2015 +0200
+++ b/src/hdalab/views/ajax.py	Tue Mar 31 02:19:38 2015 +0200
@@ -130,6 +130,19 @@
             })
     if resobj:
         cleantags(resobj)
+    elif len(master_category):
+        resobj = {
+            'label': master_category[0].label,
+            'themes': [],
+            'contents': []
+        }
+    else:
+        resobj = {
+            'label': label,
+            'themes': [],
+            'contents': []
+        }
+
     
     return HttpResponse(content=json.dumps(resobj), content_type='application/json')