"Missing endcsname inserted. Undefined control sequence" for a includegraphics

Question

everyone.

I've retaken Latex for a project a need to make, and I've been dealing with this problem for two days now. It's driving me nuts.

I've tried uninstalling texlive and texmaker fully and then installing it again, but it doesnt work.

Any help? What am I misiing?

\documentclass[10pt,a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\numberwithin{equation}{section}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{upgreek}
\usepackage{graphicx}
\usepackage{endnotes}
\usepackage{caption}
\usepackage{subcaption}
\usepackage{mathrsfs}
\usepackage[toc]{blindtext}
\usepackage{tocbibind}
\usepackage{enumerate}
\usepackage{float}
\usepackage{multirow}
\usepackage{multicol}
\usepackage[usenames]{color}
\usepackage[hidelinks]{hyperref}
\usepackage[dvipsnames]{xcolor}
\usepackage[spanish, es-tabla]{babel}
\usepackage{flushend}
\usepackage{booktabs}
\usepackage{underscore}
\usepackage{wrapfig}

\graphicspath{ {./img/} }

\author{\textit{Samuel G. Guerrero Camarero}}

\title{\textbf{ Práctica 8. El efecto Hall en semiconductores}}


\topmargin=-3cm
\oddsidemargin=-0.4cm
\textwidth=16.5cm
\textheight=25cm
\topmargin=-2cm

\begin{document}
\maketitle

\vspace*{0.1cm}
\begin{center}\rule{0.9\textwidth}{0.1mm} \end{center}
\begin{abstract}
\normalsize ESTO E EL ABSTRACT DEL INFORME, CENTRADO Y LO PRIMERO DESPUES DE TITULO Y AUTOR.

\begin{center}\rule{0.9\textwidth}{0.1mm} \end{center}
\vspace*{0.2cm}
\end{abstract}

\section{Fundamento teórico}
El efecto Hall es una consecuencia de la propia naturaleza de la corriente. Esta se basa en el moviemiento de los portadores de carga, tales como electrones, huecos, iones o cualquier combinación de los tres. Si se aplica un campo eléctrico, $\vec{B}$ en la región donde existe corriente eléctrica y en dirección perpendicular a esta, en cada portador con carga $q$ y velocidad $\vec{v}$ aparecerá la conocida \textit{Fuerza de Lorentz}, $\vec{F}_{Lorentz}$, que vendrá dada por
\begin{equation}
        \vec{F}_{Lorentz}=q\vec{v}\times\vec{B}.
\end{equation}

Cuando una componente perpendicular de campo magnético se aplica, las trayectorias de los portadores entre colisiones con otras particulas del material, como impurezas, se curvan. Esto hace que los portadores se acumulen en una cara del material. El resultado es una asimetría en la densidad de carga del cuerpo

\begin{wrapfigure}{r}{5cm}
   \includegraphics[scale=1]{hall_efect}
\end{wrapfigure}


\begin{thebibliography}{0}

    \bibitem{HALLwiki} Hall Efect, Wikipedia. \url{https://en.wikipedia.org/wiki/Hall_effect#cite_note-9}

\end{thebibliography}

\end{document}

And the error I am getting:

! Missing endcsname inserted.
<to be read again>
unhbox
l.62 \includegraphics{hall_efect}
The control sequence marked <to be read again> should
not appear between \csname and \endcsname.
! Undefined control sequence.
GenericError ...
#4 errhelp @err@ ...
l.62 \includegraphics{hall_efect}
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

Thank you in advance!

Answer 1

I get the error if I run an older TeX Live distribution. It doesn't happen with a current TeX Live 2020.

The culprit, in your case, is the underscore package. Remove it, or use

\includegraphics[scale=1]{hall\string_efect}

Unrelated: note that hyperref should be loaded after babel.