Please help with LaTeX: Cyrillic texts, when compliled, are rendered as white blank spaces

I’m writing on Cyrillic in XeLa TeX 2023 – I’m translating a book and overwriting the existing text in English with Cyrillic (Russian translation). When compiling, Cyrillic letters are not dispkayed – they are rendered as blank spaces, although Latin words and punctuation marks asre rendered normally.

From the original main.tex file in English:

I tried adding the following to the main.tex file of this project:
\usepackage[english, russian]{babel}
(to add Cyrillic coding and the new language)

Also tried
\newfontfamily{\russianfont}[Script=Cyrillic]{CMU Serif}

Also, I tried to change the font.

None of these worked. Cyrillic letters are still rendered as white blank spaces.

Please advise how to get the visible (displayable) text in Cyrillic in the existing project in English.

I don’t think fontenc should be present. You are mixing packages for the old PDFTeX engine with newer requirements for XeLaTeX or LuaLaTeX. Do you have a minimal document that demonstrates your problem. I did a minimal test which works in both XeLaTex and LuaLaTeX:

\usepackage{fontspec} % loaded by polyglossia, but included here for transparency 

\setmainfont{Alegreya Sans}

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And this compiles without any issue. Note you MUST have the correct font installed and that font must support cyrillic script or else the text will disappear (i.e. if you make a typo for the font name or the font is not properly installed in fontbook). I used a different font (Alegreya serif for cyrillic and Alegreya sans for english) just to demonstrate the font selection is working… On macOS you can easily install Alegreya (which is cyrillic, greek and latin compatible) from homebrew: brew install font-alegreya font-alegreya-sans

EDIT: Do you need the specific typographic tools from Polyglossia? If you don’t, and don’t want to mess with LaTeX for PDF production (where simple things can seem hard) and your needs are simple, Typst could be a much better solution… Or you could also, as long as you are using utf8 (which Scrivener produces and don’t need fancy options, remove polyglossia completely, XeLaTeX can show cyrillic without need for any other packages as long as the font supports it…