From d6730613df67a84071b46f10f707422cc270aaee Mon Sep 17 00:00:00 2001
From: Vanessa <lly219@gmail.com>
Date: Mon, 29 Dec 2025 21:46:23 +0800
Subject: [PATCH] :art: https://github.com/siyuan-note/siyuan/issues/16708

---
 app/src/protyle/gutter/index.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/app/src/protyle/gutter/index.ts b/app/src/protyle/gutter/index.ts
index 246253b84..5c0aeaf05 100644
--- a/app/src/protyle/gutter/index.ts
+++ b/app/src/protyle/gutter/index.ts
@@ -376,7 +376,10 @@ export class Gutter {
                             }
                         }
                     });
-                    (buttonElement.parentElement.querySelector("[data-type='fold'] > svg") as HTMLElement).style.transform = hasFold ? "rotate(90deg)" : "";
+                    const arrowElement = buttonElement.parentElement.querySelector("[data-type='fold'] > svg") as HTMLElement;
+                    if (arrowElement) {
+                        arrowElement.style.transform = hasFold ? "rotate(90deg)" : "";
+                    }
                     const doOperations: IOperation[] = [];
                     const undoOperations: IOperation[] = [];
                     Array.from(foldElement.parentElement.children).find((listItemElement) => {