
Attach (recommended) or Link to PDF file here:
[NAPEN16171380959.pdf](https://github.com/mozilla/pdf.js/files/6143802/NAPEN16171380959.pdf)

Configuration:
- Web browser and its version: Firefox 88 Nightly
- Operating system and its version: Windows 10
- PDF.js version:
- Is a browser extension: No

What went wrong? (add screenshot)
![](https://user-media-prod-cdn.itsre-sumo.mozilla.net/uploads/images/2021-03-15-10-58-27-ce2796.png)


var EEXEC_SIGNATURE = [0x65, 0x65, 0x78, 0x65, 0x63];
    var streamStartPos = stream.pos; 
    var headerBytes, headerBytesLength, block;
    try {
      headerBytes = stream.getBytes(suggestedLength);
      headerBytesLength = headerBytes.length;
    } catch (ex) {
      if (ex instanceof MissingDataException) {
        throw ex;
      }
      
      
      
    }
    if (headerBytesLength === suggestedLength) {
      
      
      
      
      block = findBlock(
        headerBytes,
        EEXEC_SIGNATURE,