问题
I have error in my LaTeX document, when run my file, have a error
! LaTeX Error: Missing \begin{document}.
and this tag \begin{document} exists in my code
\documentclass[12pt, a4paper]{article}
\usepackage{graphicx} % inserting images
\usepackage[top=3cm,right=3cm,bottom=2.5cm,left=2.5cm]{geometry}
\usepackage[colorlinks,linkcolor=blue,citecolor=red]{hyperref}
\usepackage{multirow}
\usepackage{subfig}
\usepackage{algorithm}
\usepackage{algorithmic}
%\usepackage[utf8]{inputenc}
%\usepackage{color, pdfcolmk}
%\usepackage{sweave}
% setting the margins of page
\usepackage{xepersian}
\usepackage{setspace}
\settextfont[Scale=1.2]{XB Zar}
\setlatintextfont[Scale=1.1]{XB Zar}
\setdigitfont{XB Zar}
\setcounter{secnumdepth}{3}
\SepMark{-}
\DefaultMathsDigits
%-----------------------list-------------------------------------
\renewcommand{\listfigurename}{فهرست شکل ها}
\renewcommand{\listtablename}{فهرست جدولها}
\renewcommand{\refname}{\rl{{مرجعها}\hfill}}
%---------------------end list-------------------------------------
%\usepackage{geometry}\geometry{left=35mm,right=35mm, top=30mm,bottom=30mm}
\begin{document}
\pagenumbering{gobble}
\clearpage
\thispagestyle{empty}
回答1:
When I copy the code you have shown here into Notepad++ with UTF-8 input encoding, I get the following result for the first line:
\documentclass[12pt?, ?a4paper]{article}?
From that I assume that you have non-UTF-8 characters which aren't recognized by LaTeX and thus it throws an error. Try to replace that line by
\documentclass[12pt, a4paper]{article}
As @nowox remarked in a comment, the \end{document} is missing. Make sure that you have that in your file.
来源：https://stackoverflow.com/questions/30543113/error-missing-begindocument-in-latex