diff --git a/src/components/bpmnProcessDesigner/package/penal/multi-instance/ElementMultiInstance.vue b/src/components/bpmnProcessDesigner/package/penal/multi-instance/ElementMultiInstance.vue
index 1ee68e86..331ffa2b 100644
--- a/src/components/bpmnProcessDesigner/package/penal/multi-instance/ElementMultiInstance.vue
+++ b/src/components/bpmnProcessDesigner/package/penal/multi-instance/ElementMultiInstance.vue
@@ -301,7 +301,7 @@ const approveMethod = ref()
 const approveRatio = ref(100)
 const otherExtensions = ref()
 const getElementLoopNew = () => {
-  const extensionElements = bpmnElement.value.businessObject?.extensionElements ?? []
+  const extensionElements = bpmnElement.value.businessObject?.extensionElements ?? bpmnInstances().moddle.create('bpmn:ExtensionElements', { values: [] })
   approveMethod.value = extensionElements.values.filter(
     (ex) => ex.$type === `${prefix}:ApproveMethod`
   )?.[0]?.value
diff --git a/src/components/bpmnProcessDesigner/package/penal/task/task-components/UserTask.vue b/src/components/bpmnProcessDesigner/package/penal/task/task-components/UserTask.vue
index ecd6fbf4..07bb3ed7 100644
--- a/src/components/bpmnProcessDesigner/package/penal/task/task-components/UserTask.vue
+++ b/src/components/bpmnProcessDesigner/package/penal/task/task-components/UserTask.vue
@@ -163,7 +163,7 @@ const resetTaskForm = () => {
     return
   }
 
-  const extensionElements = businessObject?.extensionElements ?? []
+  const extensionElements = businessObject?.extensionElements ?? bpmnInstances().moddle.create('bpmn:ExtensionElements', { values: [] })
   userTaskForm.value.candidateStrategy = extensionElements.values?.filter(
     (ex) => ex.$type === `${prefix}:CandidateStrategy`
   )?.[0]?.value