Return of the font cache mess (help!)

[David Feuer]

I'm running Lillypond 2.10.19.  As has happened in the past, it gets
stuck rebuilding the font database every time.  When I run fc-cache on
c:\windows\fonts, I get an error "Failed to write cache".

I don't know if it means anything, but fc-cache -s gives
fc-cache -s
Fontconfig warning: no <cachedir> elements found. Check configuration.
Fontconfig warning: adding <cachedir>/usr/var/cache/fontconfig</cachedir>
Fontconfig warning: adding <cachedir>~/.fontconfig</cachedir>
Fontconfig error: out of memory

Can anyone help?

David Feuer