And, more importantly, what can I do to fix it? No MWE, since it happens every time I use a particular font (and not when I don't or disable microtype's protrusion). These are the warnings I get:
... hyph-de-1996.tex: Package microtype Warning: Unknown slot number of character(microtype) `\k A'(microtype) in font encoding `TU' in inheritance list(microtype) `microtype.cfg/390(protrusion)'.
... hyph-de-1996.tex: Package microtype Warning: Unknown slot number of character(microtype) `\u A'(microtype) in font encoding `TU' in inheritance list(microtype) `microtype.cfg/390(protrusion)'.
And so on, repeated many times. I am using LuaLaTeX. The font is proprietary, and I own the full .otf version. Anything I can do, or ask when bringing it up with the vendor?
\k Awith the font? – Ulrike Fischer Jan 25 '21 at 08:53ĄorĂcharacters, but then I don't use them anywhere in the document, either. – Ingmar Jan 25 '21 at 08:57