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):

Ascii85Stream.prototype.readBlock = function Ascii85Stream_readBlock() {
    var TILDA_CHAR = 0x7e; 
    var Z_LOWER_CHAR = 0x7a; 
    var EOF = -1;
    var str = this.str;
    var c = str.getByte();
    while (isWhiteSpace(c)) {
      c = str.getByte();
    }
    if (c === EOF || c === TILDA_CHAR) {
      this.eof = true;
      return;
    }
    var bufferLength = this.bufferLength,
      buffer;
    var i;
    
    if (c === Z_LOWER_CHAR) {
      buffer = this.ensureBuffer(bufferLength + 4);
      for (i = 0; i < 4; ++i) {
        buffer[bufferLength + i] = 0;
      }
      this.bufferLength += 4;
    } else {
      var input = this.input;
      input[0] = c;
      for (i = 1; i < 5; ++i) {
        c = str.getByte();
        while (isWhiteSpace(c)) {
          c = str.getByte();