Errors in table, missing \endgroup inserted <inserted text> \endgroup

Question

Below is the latex example i am working on, it should generate two tables. One table with two columns, the other table is just one column. And i have a software program it makes any word in the table looks like #blabla replaced as \textcolor{green}{$#blabla$}

But i got errors, what is the problem?

It should produce a file looks like this

Below is the original code, I am not sure if the formatting has any influence for the result, so I just copied it here directly, and posted the picture above.

\documentclass[a4paper,leqno,twoside]{article}
\usepackage[utf8]{inputenc}

\title{dd}

\usepackage{amsmath}
\usepackage{color}
\usepackage{tabu}
\usepackage{longtable}
\usepackage{supertabular}

\begin{document}

\maketitle

\section{Introduction}
it is a introduction

\subsection{it is a subsection}

\begin{longtabu} to \textwidth {|>{\footnotesize}X[1 , p]| X[3 , l ]| } \hline
\endfirsthead    
\multicolumn{2}{c}    
\endhead    
\endfoot    \hline    
\endlastfoot      
sdf \newline  \newline  & >>Text \newline asdfl \textcolor{green}{$\#lksdjf$} asldkj.\newline     
\end{longtabu}    
\begin{longtabu} to \textwidth {>{\normalsize}X[p ] }        
\endfirsthead    \multicolumn{1}{c}    
\endhead    
\endfoot    
\endlastfoot    >>Text \newline >>Text    
\end{longtabu}
\end{document}

Answer 1

Would this be what you were after!. After some studies, errors were found

 \multicolumn{2}{c}{}  % 2 such cases: missing the last {}
 $>>$                  % 3 such cases: need math environment

Code

\documentclass[a4paper,leqno,twoside]{article}
\usepackage[utf8]{inputenc}

\title{dd}

\usepackage{amsmath} 
\usepackage{color} 
\usepackage{tabu} 
\usepackage{longtable} \usepackage{supertabular}

\begin{document}

\maketitle

\section{Introduction} it is a introduction

\subsection{it is a subsection}

\begin{longtabu} to \textwidth {|>{\footnotesize}X[1 , p]| X[3 , l ]| } \hline
\endfirsthead    
\multicolumn{2}{c}{}    
\endhead    
\endfoot    \hline    
\endlastfoot      
sdf \newline  \newline  & $>>$Text \newline asdfl \textcolor{green}{$\#lksdjf$} asldkj.\newline     
\end{longtabu}    
\begin{longtabu} to \textwidth {>{\normalsize}X[p ] }        
\endfirsthead    
\multicolumn{1}{c}{}  
\endhead    
\endfoot    
\endlastfoot    
$>>$Text \newline $>>$Text  
\end{longtabu}
\end{document}