Compile error unable to find error line [closed]

Question

I am unable to compile the LaTeX code in TeXnicentre to PDF. The problem is I am unable to pinpoint the source line of error by F9/shift+F9. Would be great if you could help.

Edit: Here is the MWE:

\documentclass{article}%

\usepackage{amsmath}% 
\usepackage{amsfonts}%
\usepackage{amssymb}%
\usepackage{graphicx}
\usepackage{breqn}
\usepackage{verbatim}
%\usepackage{biblatex}
\usepackage{apacite}
%-------------------------------------------
\newtheorem{theorem}{Theorem} 
\newtheorem{acknowledgement}[theorem]{Acknowledgement} 
\newtheorem{algorithm}[theorem]{Algorithm} 
\newtheorem{axiom}[theorem]{Axiom} 
\newtheorem{case}[theorem]{Case}
\newtheorem{claim}[theorem]{Claim} 
\newtheorem{conclusion}[theorem]{Conclusion} 
\newtheorem{conjecture}[theorem]{Conjecture} 
\newtheorem{corollary}[theorem]{Corollary} 
\newtheorem{criterion}[theorem]{Criterion} 
\newtheorem{definition}[theorem]{Definition} 
\newtheorem{example}[theorem]{Example} 
\newtheorem{exercise}[theorem]{Exercise} 
\newtheorem{lemma}[theorem]{Lemma}
\newtheorem{notation}[theorem]{Notation} 
\newtheorem{problem}[theorem]{Problem} 
\newtheorem{proposition}[theorem]{Proposition} 
\newtheorem{remark}[theorem]{Remark} 
\newtheorem{solution}[theorem]{Solution} 
\newtheorem{summary}[theorem]{Summary} 
\newenvironment{proof}[1][Proof]{\textbf{#1.} }{\ \rule{0.5em}{0.5em}}

\begin{document}

\title{My research paper} \author{Abhimanyu Arora}\thanks{Thanks to all in Texchange} \maketitle

\begin{abstract} This is the abstract \end{abstract}

\section{Introduction} This is the intro.

\section{Model} Here goes the model.

\section{Conclusion} This section concludes.

%\bibliographystyle{apacite}
%\bibliography{}

\appendix This is the appendix
\end{document}