无论我做什么，它都会给出这个错误 TeX 容量超出，抱歉 [输入堆栈大小=5000]。请帮忙

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

我以前从未见过这个hyper包。这似乎是问题所在。看看它，这个hyper包已经 20 年没有更新了。使用更现代的hyperref包可能是一个更好的主意。请记住，hyperref必须将其作为最后一个包加载（少数例外）。