4 months in the wrong typeface.

We inherited a detailing site whose whole identity rested on one typeface: a wide machined grotesque, the sort of face you see on an instrument cluster. It was in the theme. It was in the CSS. It was in the folder.

And it had never once rendered.

What was actually wrong

The font's character map table, the part that tells software which byte means which glyph, declared 672 bytes of data and contained 410. Design tools tolerated it, because desktop font engines are forgiving and will reconstruct what they can. Browsers are not forgiving. Every one of them rejected the face outright and fell back to a system sans.

The site looked fine. It just didn't look like the brand.

This is the worst kind of bug: no error, no warning, no console message, no broken layout. The page renders. It renders in Helvetica.

What we did about it

We repaired the file instead of replacing the typeface, kept the broken original next to it so there's never a question about what changed, and wrote a check that opens every font file we're handed before a build goes out. The repair took a day. Finding it took somebody deciding to look.

There was a second fault in the same file, a different kind, that would have stopped it rendering even if the first had been fixed. That's the takeaway: a file can be wrong in more than one way at once, and none of them announce themselves.

What to take from it

Check that your brand font is actually rendering. Not in Figma. In a browser, on the live site, by inspecting the computed font on a heading. If it says -apple-system or Arial, you've been paying for a typeface nobody has seen.