Update runtime.ts

src/pc/home/runtime.ts

@@ -237,7 +237,7 @@ export const renderMeasures = (abc: IAbc, option?: IRenderMeasuresOption) => {
     const measure = measures[i];
     text += measure.repeat ?? ""; // 重复
     text += measure.meter ?? ""; // 拍号
-    for (let j = 0; j < measure.notes.length; j++) {
+    for (let j = 0; j < measure.notes?.length; j++) {
       const note = measure.notes[j];
       const playStr = note.play?.join("") ?? "";