问：

我正在尝试为 MS PowerPoint 构建一个加载项，因此我决定测试文档中的一个示例，即：

// Link to full sample: https://raw.githubusercontent.com/OfficeDev/office-js-snippets/prod/samples/powerpoint/text/get-set-textrange.yaml
// Selects the first 10 characters of the selected shape.
await PowerPoint.run(async (context) => {
  const shapes = context.presentation.getSelectedShapes();
  const shapeCount = shapes.getCount();
  await context.sync();
  if (shapeCount.value !== 1) {
    console.warn("You must select only one shape with text in it.");
    return;
  }
  const shape = shapes.getItemAt(0);
  const textFrame = shape.textFrame.load("textRange,hasText");
  await context.sync();
  if (textFrame.hasText != true) {
    console.warn("You must select only one shape with text in it.");
    return;
  }
  const textRange = textFrame.textRange;
  textRange.load("text");
  await context.sync();
  if (textRange.text.length < 10) {
    console.warn("You must select only one shape with at least 10 characters in it.");
    return;
  }
  const textRange10 = textRange.getSubstring(0, 10);
  textRange10.setSelected();
  await context.sync();
});

在 MS PowerPoint 上运行代码时，加载 textRange 的行会引发异常：await context.sync();

异常 RichApi.Error：GeneralException

我尽我所能，但没有成功，任何帮助都是值得赞赏的