Attach (recommended) or Link to PDF file here:  [test.pdf](https://akmer.aikucun.com/a94a8fe5ccb19ba61c4c0873d391e987982fbbd3_1616477914120_83.pdf)


Configuration:
- Web browser and its version: chrome 87.0.4280.88
- Operating system and its version: windows10
- PDF.js version: 2.6.347
- Is a browser extension:

Steps to reproduce the problem:
1. just open 

What is the expected behavior? (add screenshot)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/17724610/112087066-473f8f80-8bc8-11eb-8efb-56139ec42a9c.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

let obj = this._catDict.get("Outlines");
    if (!isDict(obj)) {
      return null;
    }
    obj = obj.getRaw("First");
    if (!isRef(obj)) {
      return null;
    }
    const root = { items: [] };
    const queue = [{ obj, parent: root }];
    
    const processed = new RefSet();
    processed.put(obj);
    const xref = this.xref,
      blackColor = new Uint8ClampedArray(3);
    while (queue.length > 0) {
      const i = queue.shift();
      const outlineDict = xref.fetchIfRef(i.obj);
      if (outlineDict === null) {
        continue;
      }
      if (!outlineDict.has("Title")) {
        throw new FormatError("Invalid outline item encountered.");
      }
      const data = { url: null, dest: null };