diff -r 82da3462fce8 -r 979d9263c1c6 src/hdalab/views/ajax.py
--- a/src/hdalab/views/ajax.py	Tue Mar 31 01:44:45 2015 +0200
+++ b/src/hdalab/views/ajax.py	Tue Mar 31 02:03:37 2015 +0200
@@ -94,11 +94,11 @@
     label = request.GET.get('label', None)
     lowerlabel = label.lower()
     globtags = {}
-    resobj = None
+    resobj = {}
     master_category = WpCategory.objects.filter(label__iexact=label)[0:1]
     if len(master_category):
         resobj = subcat(master_category[0], globtags, 1, MAX_LEVEL )
-       
+    
     #datasheets = Datasheet.objects.filter(validated = True, taggedsheet__tag__label__in = tag_list, taggedsheet__order__lte = MAX_TAG_ORDER).distinct()
     datasheets = Datasheet.objects.filter(validated = True, taggedsheet__tag__label__iexact = label, taggedsheet__order__lte = ROOT_MAX_TAG_ORDER).select_related('organisation').distinct()
     for datasheet in datasheets:
@@ -128,7 +128,8 @@
                 'organization_url': datasheet.organisation.website,
                 'score': max(dsscore, rootscore)
             })
-    cleantags(resobj)
+    if resobj:
+        cleantags(resobj)
     
     return HttpResponse(content=json.dumps(resobj), content_type='application/json')