Recompiling on another newer iMac I obtain error: "./LibroOrange.tex:187: Package etoolbox Error: Toggle 'blx@lang@captions@latin' undefined."

Ulrike Fischer already linked to Cannot use polyglossia/babel with biblatex in LuaTeX: etoolbox Toggle undefined in the comments and that is indeed the same issue. The bug should be fixed in the upcoming biblatex 3.15b.

Since there was some confusion about whether or not the answer applies only for polyglossia, here is an example using babel.

The core of the answer is to have the line

providetoggle{blx@lang@captions@<language>}

if the main document language <language> has no biblatex localisation file (.lbx file). (That explains why there is an error with latin, for which there is no .lbx file, but not with ngerman, french, or english, all of which have an .lbx file.)

The following example compiles without error again

documentclass[latin]{article}
usepackage[T1]{fontenc}
usepackage[utf8]{inputenc}
usepackage{babel}
usepackage{csquotes}

usepackage[style=authoryear, backend=biber]{biblatex}

providetoggle{blx@lang@captions@latin}

addbibresource{biblatex-examples.bib}

begin{document}
Arma virumque cano autocite{sigfridsson}

printbibliography
end{document}