For each PDF/A-1 validation issue we try to explain what it means and, if possible how to resolve it. For a more technical explanation of the issue we quote the related section of the ISO 19005-1 PDF/A Specification.
The document contains an embedded font that is missing glyph width details which could affect the rendering of the document.
How can I fix it?
Use a PDF creation product that correctly encodes and embeds all fonts. We recommend Solid PDF Creator Plus.
6.3.6 - ISO 19005-1 PDF/A Specification:
For every font embedded in a conforming file, the glyph width information stored in the Widths entry of the font dictionary and in the embedded font program shall be consistent.
NOTE: This requirement is necessary to ensure predictable font rendering, regardless of whether a given reader uses the metrics in the Widths entry or those in the font program.