Cyrillic symbols are not displayed

Question

I'm trying to compile a template babel based presentation on my machine. And I can not get cyrillic symbols displayed.

The problem is that it won't produce any useful output. Build process seems to end without any errors, but text is not displayed.

I also tried to build it with pdflatex and I succeeded. Usually I use XeTeX.

Any ideas on how can I fix it? It's not that I need to use XeTeX too much, but I've wasted few hours on that and I'm curious.

Here's the MWE:

\documentclass{beamer}
\usepackage{lmodern}
\usepackage[english,russian]{babel}

% Стиль презентации

\usetheme{Warsaw}
\begin{document}
\title{Все что вы хотели знать о сферическом коне в вакууме, но боялись спросить}  
\author{Олень Северный}
\institute{Научно исследовательский институт физико-матетматических проблем}
\date{Москва, 2010} 
% Создание заглавной страницы
\frame{\titlepage} 
% Автоматическая генерация содержания
\frame{\frametitle{Содержание}\tableofcontents} 
\end{document}

Answer 1

You're using the lmodern package, which sets the document fonts to Latin Modern, but it doesn't have support for cyrillic letters. There's Computer Modern Uncode for cyrillic and greek.

For XeLaTeX, add

\usepackage{fontspec}
\setmainfont[
  Ligatures=TeX,
  Extension=.otf,
  BoldFont=cmunbx,
  ItalicFont=cmunti,
  BoldItalicFont=cmunbi,
]{cmunrm}
\setsansfont[
  Ligatures=TeX,
  Extension=.otf,
  BoldFont=cmunsx,
  ItalicFont=cmunsi,
]{cmunss}

just before \usepackage[english,russian]{babel}, assuming that cm-unicode is installed into your TeX distribution.

For LuaLaTeX it's sufficient to add

\usepackage{fontspec}
\setmainfont{CMU Serif}[Ligatures=TeX]
\setsansfont{CMU Sans Serif}[Ligatures=TeX]

and if you want to use good old pdfLaTeX, just add the usual

\usepackage[T2A]{fontenc}
\usepackage[utf8]{inputenc}

(in all cases remove the \usepackage{lmodern} line).

Note, that for pdfLaTeX the correct fonts are selected automagically after you specify the font encoding (T2A), but for LuaLaTeX and XeLaTeX you'd have to set them explicitly which is a pity.

Answer 2

I've compiled with OVERLEAF. I hope I have helped you.

\documentclass{beamer}
\usepackage{lmodern}
\usepackage[english,russian]{babel}
\usepackage[T1,T2A]{fontenc}
\usepackage[utf8]{inputenc}
% Стиль презентации

\usetheme{Warsaw}
\begin{document}
\title{Все что вы хотели знать о сферическом коне в вакууме, но боялись спросить}  
\author{Олень Северный}
\institute{Научно исследовательский институт физико-матетматических проблем}
\date{Москва, 2010} 
% Создание заглавной страницы
\frame{\titlepage} 
% Автоматическая генерация содержания
\frame{\frametitle{Содержание}\tableofcontents} 
\end{document}