No importa lo que haga, aparece este error: Se excedió la capacidad de TeX, lo siento [tamaño de la pila de entrada = 5000]. Por favor ayuda

Question

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{answers}
\usepackage{amsmath}
\usepackage{attachfile}
\usepackage{todo}
\usepackage{hyper}
\Newassociation{sol}{Solution}{ans}
\newtheorem{ex}{Exercise}
\title{Packages in LATEX}
\author{anandajiththarol }
\date{November 2020}

\begin{document}

\maketitle

\section{answers}
Answers  is package used to create question and answer sheet using latex very easily.This  package  is  a  modification  of  the   previous  style  option answers,which  has  been  in  use  for  a  few  years,  and  was  based  upon  the  TEXbook  idea of binding solutions to exercises.
\newline
\textbf{\textit{Example:}}
\Opensolutionfile{ans}[ans1]
 \subsection{Problems}
 \begin{ex}
 First exercise
 \begin{sol}
 First solution.
 \end{sol}
 \end{ex}
 \begin{ex}
 Second exercise
 \begin{sol}
 Second solution.
 \end{sol}
 \end{ex}
 \Closesolutionfile{ans}
 \subsection{Solutions}
 \input{ans1}

\section{newcommand}
Newcommand is a latex package to define new macros. Only one argument can be designated as optional, it must be the first argument, and it must appear within square brackets.  Defining macros that take multiple optional arguments or in which an optional argument appears in the middle of the argument list is possible but is somewhat complicated.
\newline
\textbf{\textit{Example}}
\newcommand\numberthis{\addtocounter{equation}{1}\tag{\theequation}} 
\begin{align*}
     x &=ut+\frac{1}{2}*(at^2)\\
     x &=\frac{1}{2}*gt^2\\
      g &=\frac{2x}{t^2} \numberthis\label{eq1}
\end{align*}
In the above quation a custom macro, numberthis is used to label an equation.
\section{Attachfile}
his package defines an attachfilecommand that lets you attach arbitrary files to a pdf document. These files are embedded right in the pdf file, so they get transmitted along with it. The package also gives you control over the corresponding icon’s properties and various other associated metadata.
\newline
\textbf{\textit{Example}}
\attachfile{attach.txt}\\
Here a sample txt is attached to the document using the attchfile package.\\

\end{document}

Answer 1

Nunca antes había visto el hyperpaquete. Parece ser el problema. Mirándolo, el hyperpaquete no se ha actualizado en 20 años. Probablemente sea una mejor idea utilizar el hyperrefpaquete más moderno. Recuerde que hyperrefdebe cargarse como último paquete (con un pequeño número de excepciones).