"... error reading font file ... emmentaler-14.otf"

[Evans Winner]

Hi, I am wondering if anyone can give me an idea of what is
going on below.  This is the tail end of my Makefile output
that calls lilypond-book.  It looks as if there is perhaps
something wrong with a font that Lilypond is trying to read,
but I don't know for sure.  The file does exist, and I am
able to open it in the Windows 7 default font file viewer.

Also, I don't actually know if the error at the end of the
listing below is related or not to the one at the top.

When I see this error, make terminates, but I am often able
to run it a couple more times and eventually the project
completes its compile, though whether there is something
wrong hiding in the output I am not sure (it is many pages
long).

I am not sure what other information would be useful, or how
to intelligently narrow the possibilities down.  For what it
may be worth, the call (after variable expansions) in my
Makefile looks like:

python "C:/Program Files/LilyPond/usr/bin/lilypond-book.PY" 
--latex-program=lualatex --output=build piano.lytex

I did try 2.19.4 to see if there was a difference; there
was, but I think I should post that under a different recent
thread.

============

<snip many lines where it appears to be rendering files>

fatal error: error reading font file c:/Program 
Files/LilyPond/usr/share/lilypond/current/fonts/otf/emmentaler-14.otf: cannot 
open resource
lilypond-book.PY (GNU LilyPond) 2.19.3
Reading piano.lytex...
Running `lualatex' on file `c:\users\evansw\appdata\local\temp\tmpqme81f.tex' 
to detect default page settings.

lilypond-book.PY: warning: Unable to auto-detect default settings:

lilypond-book.PY: warning: cannot detect textwidth from LaTeX
Dissecting...
Writing snippets...
Processing...
Running lilypond...
command failed: lilypond --formats=ps -dbackend=eps  -I  "."  -I  ".." 
--formats=eps  -deps-box-padding=3.000000  -dread-file-list 
-dno-strip-output-dir  
"c:\Users\evansw\cloud\piano-sets\build\snippet-names-1124436941.ly"
Child returned 1
make: *** [build/piano.tex] Error 1

Compilation exited abnormally with code 2 at Fri Apr 11 17:41:52