Index: sites/all/modules/taxonomy_pivot/taxonomy_pivot.module
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- sites/all/modules/taxonomy_pivot/taxonomy_pivot.module	(revision )
+++ sites/all/modules/taxonomy_pivot/taxonomy_pivot.module	(revision )
@@ -160,7 +160,7 @@
   }
 
   // Add new filter.
-  if ($form_state["triggering_element"]["#name"] == "filter-add") {
+  if (isset($form_state["triggering_element"]) && $form_state["triggering_element"]["#name"] == "filter-add") {
     $new_filter = $form_state["values"]["filters"]["filter-select"];
 
     $form['config']['filters']['filter-fields'][$filter_count] = array(