Attach (recommended) or Link to PDF file here:

Configuration:
- Web browser and its version: Chrome 63.0.3239.132 
- Operating system and its version: Windows 10
- PDF.js version: using your official demo project
- Is a browser extension: No

Steps to reproduce the problem:
1.  Just load attached pdf
2.

What is the expected behavior? (add screenshot)
[E-WG18_105147.pdf](https://github.com/mozilla/pdf.js/files/1634833/E-WG18_105147.pdf)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/29802177/34986271-3ca71a5c-fab7-11e7-95e8-1739dda3cd04.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

info(
          "Attempting to fix invalid indexToLocFormat in head table: " +
            indexToLocFormat
        );
        
        
        
        
        
        
        
        
        
        const numGlyphsPlusOne = numGlyphs + 1;
        if (locaLength === numGlyphsPlusOne << 1) {
          
          data[50] = 0;
          data[51] = 0;
        } else if (locaLength === numGlyphsPlusOne << 2) {
          
          data[50] = 0;
          data[51] = 1;
        } else {
          throw new FormatError(
            "Could not fix indexToLocFormat: " + indexToLocFormat
          );
        }
      }
    }
    function sanitizeGlyphLocations(