Check for null column display_name in table renderer

resources/frontend_client/app/query_builder/visualization_table.react.js

@@ -152,7 +152,8 @@ export default React.createClass({
 
     tableHeaderRenderer: function(columnIndex) {
         var column = this.props.data.cols[columnIndex],
-            colVal = (column !== null) ? (column.display_name.toString() || column.name.toString()) : null;
+            colVal = (column && column.display_name && column.display_name.toString()) ||
+                     (column && column.name && column.name.toString());
 
         var headerClasses = cx({
             'MB-DataTable-header' : true,