ui.font.unusable
a font file under the project's ui/fonts/ (or named by an @font-face rule) cannot be read as a font (no faces, no family name, or no mapped characters); that one font is skipped and the rest of the chain, then the engine's fallbacks, draw. A font named with --font / the font environment variable that cannot be read is an error naming that file instead
| Severity | warning |
Meaning
a font file under the project's ui/fonts/ (or named by an @font-face rule) cannot be read as a font (no faces, no family name, or no mapped characters); that one font is skipped and the rest of the chain, then the engine's fallbacks, draw. A font named with --font / the font environment variable that cannot be read is an error naming that file instead
Fix
replace the file with a working .ttf/.otf, or delete it; the starter fonts under <sdk>/fixtures/render/fonts/ are safe to copy