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):

const streamRef = this._catDict.getRaw("Metadata");
    if (!isRef(streamRef)) {
      return shadow(this, "metadata", null);
    }
    const suppressEncryption = !(
      this.xref.encrypt && this.xref.encrypt.encryptMetadata
    );
    const stream = this.xref.fetch(streamRef, suppressEncryption);
    let metadata = null;
    if (isStream(stream) && isDict(stream.dict)) {
      const type = stream.dict.get("Type");
      const subtype = stream.dict.get("Subtype");
      if (isName(type, "Metadata") && isName(subtype, "XML")) {
        
        
        
        
        try {