diff --git a/frontend/app/zh-forms/tabs/tab9/zh-form-tab9.component.ts b/frontend/app/zh-forms/tabs/tab9/zh-form-tab9.component.ts
index 76ee040b..7fe8878b 100755
--- a/frontend/app/zh-forms/tabs/tab9/zh-form-tab9.component.ts
+++ b/frontend/app/zh-forms/tabs/tab9/zh-form-tab9.component.ts
@@ -51,5 +51,6 @@ export class ZhFormTab9Component implements OnInit {
   ngOnDestroy() {
     if (this.$_getTabChangeSub) this.$_getTabChangeSub.unsubscribe();
     if (this.$_currentZhSub) this.$_currentZhSub.unsubscribe();
+    this.hierarchy.warning = '';
   }
 }