My font setup is like this:

\startmode[OPTIMANOVA]
\definefontfamily
[bookfont]
[ss]
[Optima nova LT Pro]
[tf=style:Regular,
bf=style:Medium,
it=style:Italic,
bi=style:Medium Italic]
\setupbodyfont[bookfont,10pt]
\stopmode
\startmode[OPTIMA]
\definefontfamily
[bookfont]
[ss]
[Optima]
[tf=style:Regular,
bf=style:Bold,
it=style:Italic,
bi=style:Bold Italic]
\setupbodyfont[bookfont,10pt]
\stopmode

Now, both worked earlier today. But I’ve lost the old Optima font somehow. If I now try —mode=OPTIMA I get:

selectfont      > the requested font 'Optima' has no files for the 'tf' alternative, Latin Modern is used instead.

and the document is set in Latin Modern Sans Serif. Another OpenType Postscript font like Chaparral Pro works. Another TrueType like Century Gothic does not. I seem not to be able to load any TrueType font anymore.

I recall there being some way to rebuild a font cache of LMTX ConTeXt but I can’t find the instructions. Can someone enlighten me?