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):

}
      delete tables.glyf;
      delete tables.loca;
      delete tables.fpgm;
      delete tables.prep;
      delete tables["cvt "];
      this.isOpenType = true;
    } else {
      if (!tables.loca) {
        throw new FormatError('Required "loca" table is not found');
      }
      if (!tables.glyf) {
        warn('Required "glyf" table is not found -- trying to recover.');
        
        tables.glyf = {
          tag: "glyf",
          data: new Uint8Array(0),
        };
      }
      this.isOpenType = false;
    }
    if (!tables.maxp) {
      throw new FormatError('Required "maxp" table is not found');
    }
    font.pos = (font.start || 0) + tables.maxp.offset;
    const version = font.getInt32();
    const numGlyphs = font.getUint16();
    if (
      properties.scaleFactors &&
      properties.scaleFactors.length === numGlyphs &&