diff --git a/combo/apps/dataviz/models.py b/combo/apps/dataviz/models.py
index 4224c937..73f046cd 100644
--- a/combo/apps/dataviz/models.py
+++ b/combo/apps/dataviz/models.py
@@ -161,7 +161,7 @@ class ChartNgCell(CellBase):
 
     def get_cell_extra_context(self, context):
         ctx = super(ChartNgCell, self).get_cell_extra_context(context)
-        if self.chart_type == 'table':
+        if self.chart_type == 'table' and self.cached_json:
             try:
                 chart = self.get_chart(raise_if_not_cached=not(context.get('synchronous')))
             except UnsupportedDataSet:
diff --git a/combo/apps/dataviz/templates/combo/chartngcell.html b/combo/apps/dataviz/templates/combo/chartngcell.html
index 0986ab09..7a7bf34c 100644
--- a/combo/apps/dataviz/templates/combo/chartngcell.html
+++ b/combo/apps/dataviz/templates/combo/chartngcell.html
@@ -1,6 +1,8 @@
 {% load i18n %}
 {% if cell.title %}<h2>{{cell.title}}</h2>{% endif %}
-{% if cell.chart_type == "table" %}
+{% if not cell.cached_json %}
+<div class="warningnotice">{% trans "Unavailable data." %}</div>
+{% elif cell.chart_type == "table" %}
 {{table|safe}}
 {% else %}
 <div style="min-height: {{cell.height}}px">
diff --git a/combo/apps/dataviz/templates/combo/chartngcell_form.html b/combo/apps/dataviz/templates/combo/chartngcell_form.html
index aafc5394..b0717869 100644
--- a/combo/apps/dataviz/templates/combo/chartngcell_form.html
+++ b/combo/apps/dataviz/templates/combo/chartngcell_form.html
@@ -1,6 +1,6 @@
 <div style="position: relative">
 {{ form.as_p }}
-{% if cell.chart_type != "table" and cell.is_relevant %}
+{% if cell.cached_json and cell.chart_type != "table" and cell.is_relevant %}
 <div style="position: absolute; right: 0; top: 0; width: 300px; height: 150px">
   <embed type="image/svg+xml" src="{% url 'combo-dataviz-graph' cell=cell.id %}?width=300&height=150"/>
 </div>
diff --git a/combo/apps/dataviz/views.py b/combo/apps/dataviz/views.py
index 54d28314..9810d6ee 100644
--- a/combo/apps/dataviz/views.py
+++ b/combo/apps/dataviz/views.py
@@ -15,7 +15,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from django.core.exceptions import PermissionDenied
-from django.http import HttpResponse
+from django.http import HttpResponse, Http404
 from django.utils.translation import ugettext_lazy as _
 
 from combo.utils import get_templated_url, requests
@@ -34,6 +34,8 @@ def dataviz_graph(request, *args, **kwargs):
         raise PermissionDenied()
     if not cell.is_visible(request.user):
         raise PermissionDenied()
+    if not cell.cached_json:
+        raise Http404('misconfigured cell')
     try:
         chart = cell.get_chart(
                 width=int(request.GET.get('width', 0)) or None,
diff --git a/tests/test_dataviz.py b/tests/test_dataviz.py
index 648516ca..fa4c5abf 100644
--- a/tests/test_dataviz.py
+++ b/tests/test_dataviz.py
@@ -428,6 +428,14 @@ def test_chartng_cell_view(app, normal_user):
             resp = app.get('/api/dataviz/graph/1/?width=400', status=200)
             assert '>10.0%<' in resp.text
 
+            # cell with missing cached_json (probably after import and missing
+            # bijoe visualisation)
+            cell.chart_type = 'table'
+            cell.save()
+            ChartNgCell.objects.filter(id=cell.id).update(cached_json={})
+            resp = app.get('/')
+            assert 'warningnotice' in resp.text
+
 
 def test_chartng_cell_manager(app, admin_user):
     page = Page(title='One', slug='index')