如何解决Miktex 控制台编译中的错误？

Question

尝试在控制台模式下编译我的 .tex 文件时出现以下错误：“进入扩展模式 <C:\Users\Documents\myfile.tex> Latex2e <2021-11-15> 补丁级别 1 L3 编程层 <2022-02-24> ！未定义的控制序列 1.2\section 这是否意味着我的 .tex 文件有错误？我应该执行哪些命令才能从控制台获取 pdf 文件？

For example,the following code compiles correctly
\documentclass[12pt, letterpaper, twoside]{article}
\usepackage[utf8]{inputenc}

\title{First document}
\author{Lucy \thanks{Me}}
\date{11th of August}

\begin{document}

\begin{titlepage}
\maketitle
\end{titlepage}

In this document some extra packages and parameters
were added. There is an encoding package
and pagesize and fontsize parameters.

\end{document}

但俄罗斯图书馆的增设犯了一个错误

\documentclass[12pt, letterpaper, twoside]{article}
\usepackage[utf8]{inputenc}
\usepackage[russian,english]{babel}


\title{First document}
\author{Lucy \thanks{Me}}
\date{11th of August}

\begin{document}

\begin{titlepage}
\maketitle
\end{titlepage}

In this document some extra packages and parameters
were added. There is an encoding package
and pagesize and fontsize parameters.
\selectlanguage{russian}
Привет
\end{document}

以下是使用 pdflatex 控制台正确运行的代码：

\documentclass{article}

\usepackage[T2A,T1]{fontenc}

\usepackage[utf8]{inputenc}
\usepackage{multicol}
\usepackage[russian,english]{babel}

\usepackage{graphicx}   
\usepackage{multirow}   
\usepackage{amsthm}
\usepackage{array}      
\usepackage{float}
\usepackage[table]{xcolor}
\usepackage{filecontents}
\usepackage{hyperref} 
\usepackage{datatool} %for database
\usepackage{markdown} %for .txt data


\begin{document}
\selectlanguage{russian}

\input{Parameters}
\input{Title}

\tableofcontents


\input{first_section}           % here is the addition .tex file
\input{second_section}           
\end{document}

我的日志文件内容如下：

Pdflatex: security risk: running with elevated privileges
This is pdfTex, Version 3.141592653-2.6-1.40.24 <MiKTeX 22.3> <preloaded format = pdflatex.fmt>
Restricted \write18 enabled.
Entering extended mode
<C:/Users/ B/Documents/main.tex
LaTeX2e <2021-11-15> patch level 1
L3 programming layer <2022-02-24>
<C:\Program Files\MiKTeX\tex/latex/base\article.cls
Document Class: article 2021/10/04 v1.4n Standard LaTeX document class
<C:\Program Files\MiKTeX\tex/latex/base\size10.clo>>
<C:\ Program Files\MiKTeX\tex/latex/base\fontenc.sty
========================================================================
Unfortunately, the package Cyrillic could not be installed.
Please check the log file:
C:\Users\  B  \AppData\Local\MiKTeX\miktex\log\pdflatex.log
========================================================================

Package foentenc Error: Encoding file ‘t2aenc.def’ not found.
<fontenc>       You might have misspelt the name of the encoding.

See the fontenc package documentation for explanation.
Type H<return> for immediate help.
…
l.111 \ProcessOptions*