diff --git a/expert/browser/results.pt b/expert/browser/results.pt
index 2fd8129..4a04496 100644
--- a/expert/browser/results.pt
+++ b/expert/browser/results.pt
@@ -70,7 +70,8 @@
 
 <metal:state define-macro="state">
   <tal:column define=" value python:col.getDisplayValue(row)">
-    <img tal:attributes="src string:$resourceBase${value/icon};
+    <img tal:condition="value"
+         tal:attributes="src string:$resourceBase${value/icon};
                          alt value/title;
                          title value/title" />
   </tal:column>
diff --git a/expert/field.py b/expert/field.py
index 2ff64af..ff813cb 100644
--- a/expert/field.py
+++ b/expert/field.py
@@ -109,6 +109,8 @@ class StateField(Field):
     def getDisplayValue(self, row):
         if IStateful.providedBy(row.context):
             stf = row.context
+        elif row.context is None:
+            return None
         else:
             stf = component.getAdapter(row.context, IStateful, 
                                         name=self.statesDefinition)