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 cacheEntry = this._cacheMap.get(num);
      if (cacheEntry !== undefined) {
        
        
        if (cacheEntry instanceof Dict && !cacheEntry.objId) {
          cacheEntry.objId = ref.toString();
        }
        return cacheEntry;
      }
      let xrefEntry = this.getEntry(num);
      if (xrefEntry === null) {
        
        this._cacheMap.set(num, xrefEntry);
        return xrefEntry;
      }
      if (xrefEntry.uncompressed) {
        xrefEntry = this.fetchUncompressed(ref, xrefEntry, suppressEncryption);
      } else {
        xrefEntry = this.fetchCompressed(ref, xrefEntry, suppressEncryption);
      }
      if (isDict(xrefEntry)) {
        xrefEntry.objId = ref.toString();
      } else if (isStream(xrefEntry)) {
        xrefEntry.dict.objId = ref.toString();
      }
      return xrefEntry;
    },
    fetchUncompressed(ref, xrefEntry, suppressEncryption = false) {