The problem I was having (see below) has been resolved, finally. It seems that some of my 7 pt cmr and cmmi fonts somehow became corrupted. Any file using the default 10 pt size for "normal" uses 7 pt for _inline_ fractions, sub and superscripts, and the limits on integrals or sums. The corrupted 7 pt font files then caused the errors when choosing the View > pdflatex or File > Print. After it became clear that it wasn't just one 7 pt font file that was corrupted, I reinstalled TeX and everything works just fine.
I want to thank the list for its helpful suggestions along the way, especially Herbert Voss, Ronald Florence, Stephen Buonopane, Bo Peng, and Andre Poenitz. Bruce Bruce Pourciau wrote: > > Here's the problem I've been having: in any lyx file which contains (in > mathmode) a fraction or a sub or superscript, both View > pdflatex and > File > Print produce an error message. (LyX/Mac, LyX 1.3.4, Mac 10.3.4)
