"OC" == Oliver Corff writes:

 OC> To whom it may concern: I ran a compilation test on the the
 OC> complete list of file names of the LH fonts. The file name list
 OC> was script-generated (a perl script grepping all .fd files for
 OC> script/size-combinations).

 OC> If not already known to you I'd like to report that with
 OC> mfmode=ljfive the following fonts failed to be compiled:

 OC> rx{fb,fs}{2986,3583} rx{ff,fi}{0500,0600,0700,0800}

 OC> thus a total of 12 fonts failed.

are you able to generate the corresponding EC fonts? i.e.:
ec{fb,fs}{2986,3583} ec{ff,fi}{0500,0600,0700,0800}

I had problems with these fonts too, and it seems that the parameters
in the EC fonts are bad.

in particular, i had problems generating the following EC fonts:

ecbm{0600,0800}
ecfb{2488,2986,3583}
ecff{0500,0600,0700,0800}
ecfi{0500,0600,0700,0800}
ecfs{2488,2986,3583}

and also ecit{2986,3583} at big resolution.

As the LH fonts are based on parameters of EC fonts, the problems of
EC fonts migrate to LH fonts. :(

Best,
v.