diff --git a/plugins/ktcore/admin/conditions.php b/plugins/ktcore/admin/conditions.php
index 39ab4bf..e7e55dc 100755
--- a/plugins/ktcore/admin/conditions.php
+++ b/plugins/ktcore/admin/conditions.php
@@ -119,7 +119,10 @@ class KTConditionDispatcher extends KTAdminDispatcher {
             if(count($aSubgroup['values'])) {
                 foreach ($aSubgroup['values'] as $iv => $t) {
                     $datavars =& $aSubgroup['values'][$iv];
-		    $oCriterion = $oCriteriaRegistry->getCriterion($datavars['type']);
+                    $oCriterion = $oCriteriaRegistry->getCriterion($datavars['type']);
+                    if($oCriterion == null || $oCriterion == "" || PEAR:isError($oCriterion)) {
+                        $this->errorRedirectToMain('Criterion error');
+                    }
                     $datavars['typename'] = $oCriterion->sDisplay;
                     $datavars['widgetval'] = $oCriterion->searchWidget(null, $datavars['data']);
                 }
diff --git a/search/booleanSearch.php b/search/booleanSearch.php
index a483024..0f77442 100755
--- a/search/booleanSearch.php
+++ b/search/booleanSearch.php
@@ -276,6 +276,9 @@ class BooleanSearchDispatcher extends KTStandardDispatcher {
         if(!empty($subgroup['values'])) {
             foreach($subgroup['values'] as $value) {
                 $oCriterion =& $oCriteriaRegistry->getCriterion($value['type']);
+                if($oCriterion == null || $oCriterion == "" || PEAR:isError($oCriterion)) {
+                    $this->errorRedirectToMain('Criterion error');
+                }
                 $aGroup[] = $oCriterion->parameterDisplay($value['data']);
             }
         }