diff --git a/application/forms/SaveEventRuleForm.php b/application/forms/SaveEventRuleForm.php
index 89dc645f..09bd80a9 100644
--- a/application/forms/SaveEventRuleForm.php
+++ b/application/forms/SaveEventRuleForm.php
@@ -528,6 +528,10 @@ private function fetchDbValues(): array
             }
         }
 
+        if (! isset($config['rule_escalation'])) {
+            $config['rule_escalation'] = [];
+        }
+
         $config['showSearchbar'] = ! empty($config['object_filter']);
 
         return $config;