Hi, where did you download Lilypond from? With macOS Mojave (10.14) you need the following version (the first) from here https://lilypond.org/doc/v2.23/Documentation/web/macos-x : 
Your or similar error with LilyPond on macOS Mojave was described here: https://gitlab.com/lilypond/lilypond/-/issues/6143 However, the workaround described there is somewhat technical, maybe it will also work with the version of the above download link. Alternatively, you can download and try the developer version for macOS: https://lilypond.org/doc/v2.23/Documentation/web/development You can add different/multiple versions of Lilypond in Frescobaldi (see the second screenshot from your email) Good luck Sam > On 4. Jan 2025, at 09:20, Elisabetta Senesi <elisen...@gmail.com> wrote: > > Hi, > > Please find attached all the information and what’s going on. > > Please help, I am new on this. > > Thanks in advance, > > E. > > <Screenshot 2025-01-04 at 09.15.56.png> > > <Screenshot 2025-01-04 at 09.19.45.png> > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > http://elisabettasenesi.me/me.html > > > >