Errors while running poster code in texmaker

Question

I took a sample from my colleague to create a math poster but it is not running in texmaker. Line 216 shows various errors. Can some one check what I am missing here. I have never created a poster in latex before. Thanks!

Here is the code. Texmaker shows error in line 94 , the one with "\endframe"

\documentclass[final,hyperref={pdfpagelabels=false}]{beamer}
\usepackage[orientation=portrait,size=a0,scale=1.3]{beamerposter} % Use the beamerposter package for laying out the poster with a portrait orientation and an a0 paper size
\usetheme{epyt} 
\usepackage[english]{babel} 
\usepackage{amsmath,amsthm,amssymb,latexsym} 
\usefonttheme[onlymath]{serif} % Uncomment to use a Serif font within math environments
\boldmath % Use bold for everything within the math environment
\usepackage{booktabs} % Top and bottom rules for tables
\graphicspath{{figures/}} % Location of the graphics files
\usecaptiontemplate{\small\structure{\insertcaptionname~\insertcaptionnumber: }\insertcaption} 
\title{\LARGE lipsum} % Poster title
\author{ABC} % Author(s)
\institute{jjkl} % Institution(s)
\newcommand{\rightfoot}{abc@gmail.com} % Right footer text
\begin{document}
\addtobeamertemplate{block end}{}{\vspace*{1ex}} % White space under blocks
\begin{frame}[t] % The whole poster is enclosed in one beamer frame
\begin{columns}[t] % The whole poster consists of two major columns, each of which can be subdivided further with another \begin{columns} block - the [t] argument aligns each column's content to the top
\begin{column}{.02\textwidth}\end{column} % Empty spacer column
\begin{column}{.455\textwidth} % The first column
\begin{block}{nn}
\begin{itemize}
\item A Process X is called a abc if it satisfies the following:
\begin{itemize}
\item m
\item lip
\item sum \hspace{2cm} $s \leq t$
\end{itemize}
\item b
\item following
\begin{itemize}
\item b
\item m
\item n 
\end{itemize}
\item kiol
\begin{itemize}
\item nh
\item jk
\item Symmetry
\item huj
\item  able.
\end{itemize}
\end{itemize}
\end{block}
\begin{block}{nnj}
\begin{itemize}
\item X 
\end{itemize}
\begin{itemize}
\item x
\item c
\item u
\end{itemize}
\item h
\end{itemize}
abnhjkk
\end{block}
\begin{block}{References}
\begin{itemize}
\item asdf
\end{itemize}        
\end{block}
\end{column} % End of the first column
\begin{column}{.02\textwidth}\end{column} % Empty spacer column
 \begin{column}{.5\textwidth} % The second column
\begin{block}{abn}
\begin{itemize}
\item following prop:
\begin{itemize}
\item mkl
\item jk
\item jk
\item sde 
\end{itemize}
\item jk
\begin{eqnarray}
\label{4b8}
\lVert b(t,x)- b(t,y) \rVert +\lVert \sigma(t,x)- \sigma(t,y) \rVert \leq C_n\lVert x-y \rVert \\ \label{4b9}
\lVert b(t,x)\rVert^2 + \lVert b(t,x)\rVert^2 \leq C^2(1+ \lVert x \rVert^2)
\end{eqnarray}
t
\end{itemize}
\end{block}
\begin{block}{abc}
xyz
\end{block}
\setbeamercolor{block title}{fg=black,bg=red!70} % Change the block title color
\begin{block}{Acknowledgments}
bla bla
\end{block}
\end{column} % End of the second column
\end{columns} % End of all the columns in the poster
\end{frame}  % End of the enclosing frame
\end{document}

Answer 1

The code was missing either a \begin{itemize}. See comment in code at ~line no. 64

\documentclass[final,hyperref={pdfpagelabels=false}]{beamer}

\usepackage[orientation=portrait,size=a0,scale=1.3]{beamerposter} % Use the beamerposter package for laying out the poster with a portrait orientation and an a0 paper size
\usetheme{epyt} 
\usepackage[english]{babel} 
\usepackage{amsmath,amsthm,amssymb,latexsym} 
\usefonttheme[onlymath]{serif} % Uncomment to use a Serif font within math environments
\boldmath % Use bold for everything within the math environment
\usepackage{booktabs} % Top and bottom rules for tables
\graphicspath{{figures/}} % Location of the graphics files
\usecaptiontemplate{\small\structure{\insertcaptionname~\insertcaptionnumber: }\insertcaption} 


\title{\LARGE lipsum} % Poster title
\author{ABC} % Author(s)
\institute{jjkl} % Institution(s)

\newcommand{\rightfoot}{abc@gmail.com} % Right footer text
\addtobeamertemplate{block end}{}{\vspace*{1ex}} % White space under blocks
\setbeamercolor{block title}{fg=black,bg=red!70} % Change the block title color

\begin{document}
\maktitle

\begin{frame}[t] % The whole poster is enclosed in one beamer frame

\begin{columns}[t] % The whole poster consists of two major columns, each of which can be subdivided further with another \begin{columns} block - the [t] argument aligns each column's content to the top
\begin{column}{.02\textwidth}\end{column} % Empty spacer column
    \begin{column}{.455\textwidth} % The first column
        \begin{block}{nn}
            \begin{itemize}
            \item A Process X is called a abc if it satisfies the following:
                \begin{itemize}
                \item m
                \item lip
                \item sum \hspace{2cm} $s \leq t$
                \end{itemize}
                \item b
                \item following
                \begin{itemize}
                \item b
                \item m
                \item n 
                \end{itemize}
                \item kiol
                \begin{itemize}
                \item nh
                \item jk
                \item Symmetry
                \item huj
                \item  able.
                \end{itemize}
            \end{itemize}
        \end{block}

        \begin{block}{nnj}
            \begin{itemize}
            \item X 
            \end{itemize}
                \begin{itemize}
                \item x
                \item c
                \item u
                \end{itemize}
            \begin{itemize} % <- either missing 
            \item h         % <- lonely item as shown in error log
            \end{itemize}   % <- or superfluous
            abnhjkk
        \end{block}

        \begin{block}{References}
            \begin{itemize}
            \item asdf
            \end{itemize}        
        \end{block}
    \end{column} % End of the first column

    \begin{column}{.02\textwidth}
    \end{column} % Empty spacer column

        \begin{column}{.5\textwidth} % The second column
            \begin{block}{abn}
                \begin{itemize}
                \item following prop:
                    \begin{itemize}
                    \item mkl
                    \item jk
                    \item jk
                    \item sde 
                    \end{itemize}
                \item jk
                    \begin{eqnarray}
                    \label{4b8}
                    \lVert b(t,x)- b(t,y) \rVert +\lVert \sigma(t,x)- \sigma(t,y) \rVert \leq C_n\lVert x-y \rVert \\ \label{4b9}
                    \lVert b(t,x)\rVert^2 + \lVert b(t,x)\rVert^2 \leq C^2(1+ \lVert x \rVert^2)
                    \end{eqnarray}
                t
                \end{itemize}
            \end{block}

                \begin{block}{abc}
                xyz
                \end{block}

                \begin{block}{Acknowledgments}
                bla bla
                \end{block}
        \end{column} % End of the second column
    \end{columns} % End of all the columns in the poster
\end{frame}  % End of the enclosing frame
\end{document}