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):

if (parser.buf1 instanceof Cmd && parser.buf1.cmd === "endobj") {
          parser.shift();
        }
        if (isStream(obj)) {
          continue;
        }
        const num = nums[i],
          entry = this.entries[num];
        if (entry && entry.offset === tableOffset && entry.gen === i) {
          if (
            typeof PDFJSDev === "undefined" ||
            PDFJSDev.test("!PRODUCTION || TESTING")
          ) {
            assert(
              obj !== undefined,
              'fetchCompressed: The "obj" cannot be undefined.'
            );
          }
          this._cacheMap.set(num, obj);
        }
      }
      xrefEntry = entries[xrefEntry.gen];
      if (xrefEntry === undefined) {
        throw new XRefEntryException(`Bad (compressed) XRef entry: ${ref}`);
      }
      return xrefEntry;
    },
    async fetchIfRefAsync(obj, suppressEncryption) {