A PDF or PDF-compatible .ai whose ToUnicode map gives some glyphs U+FFFD (as
some files do for the digits of an embedded CID font) imported those glyphs as
type showing the replacement character, so every digit came in as "�".
U+FFFD now counts as no mapping. Such a glyph takes its character from the
embedded font where it can (Adobe's CID tables for CID-keyed CFF, as before,
then the font program's own cmap), and otherwise keeps its outline from the
embedded font, so it looks as the file draws it. The import warns which font
had characters the file doesn't name.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>