
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)


tables["cvt "],
        maxFunctionDefs
      );
      if (!hintsValid) {
        delete tables.fpgm;
        delete tables.prep;
        delete tables["cvt "];
      }
      
      
      sanitizeMetrics(
        font,
        tables.hhea,
        tables.hmtx,
        numGlyphsOut,
        dupFirstEntry
      );
      if (!tables.head) {
        throw new FormatError('Required "head" table is not found');
      }
      sanitizeHead(tables.head, numGlyphs, isTrueType ? tables.loca.length : 0);
      var missingGlyphs = Object.create(null);
      if (isTrueType) {
        var isGlyphLocationsLong = int16(
          tables.head.data[50],
          tables.head.data[51]
        );
        var glyphsInfo = sanitizeGlyphLocations(
          tables.loca,
          tables.glyf,