仅字母 ì 出现错误

Question

我收到字母 ì 的错误，但其他重音字母 àèòù 没有错误，我在下面发布了序言（请查看下面的编辑，我发布的代码并不重要）：

\documentclass[10pt, aspectratio=1610]{beamer}

\usepackage{media9}
\usepackage{amssymb,amsmath,amsthm,enumerate}
\usepackage[utf8]{inputenc}
\usepackage{array}
\usepackage[parfill]{parskip}
\usepackage{graphicx}
\usepackage{caption}
\usepackage{subcaption}
\usepackage{bm}
\usepackage{amsfonts,amscd}
\usepackage[]{units}
\usepackage{listings}
\usepackage{multicol}
\usepackage{multirow}
\usepackage{tcolorbox}
\usepackage{physics}
\usepackage{svg}
\usepackage{dsfont}
\usepackage{tikz}
\usetikzlibrary{shapes.geometric}

\newcommand\paraitem{%
 \quad
 \makebox[\labelwidth][r]{%
 \makelabel{%
 \usebeamertemplate{itemize \beameritemnestingprefix item}}}\hskip\labelsep}

\newcommand\NoIndent[1]{%
    \par\vbox{\parbox[t]{\linewidth}{#1}}%
}

% Enable colored hyperlinks
\hypersetup{colorlinks=true}
\hypersetup{linkcolor=orangeEX}

% The following three lines are for crossmarks & checkmarks
\usepackage{pifont}% http://ctan.org/pkg/pifont
\newcommand{\cmark}{\ding{51}}%
\newcommand{\xmark}{\ding{55}}%

% Numbered captions of tables, pictures, etc.
\setbeamertemplate{caption}[numbered]

\theoremstyle{remark}
\newtheorem*{remark}{Remark}
\theoremstyle{definition}

\usetheme{Stanford} 
\input{./style_files_unipd/my_beamer_defs.sty}
\logo{\includegraphics[height=0.53in]{./style_files_unipd/unipd_logo_bg.png}}

% commands to relax beamer and subfig conflicts
% see here: https://tex.stackexchange.com/questions/426088/texlive-pretest-2018-beamer-and-subfig-collide
\makeatletter
\let\@@magyar@captionfix\relax
\makeatother

\title[Sample title]{Sample title}

\begin{document}

\author[Thomas Jhonson]{
    \begin{tabular}{c} 
    \Large
    Thomas Jhonson\\
    \footnotesize \href{mailto:[email protected]}{[email protected]}
\end{tabular}
\vspace{-4ex}}

\institute{
    \vskip 5pt
    \begin{figure}
        \centering
        \begin{subfigure}[t]{0.5\textwidth}
            \centering
            \includegraphics[width=1.00in]{./style_files_unipd/unipd_logo_con_testo.png}
        \end{subfigure}%
        ~ 
        \begin{subfigure}[t]{0.5\textwidth}
            \centering
            \includegraphics[width=1.00in]{./style_files_unipd/logoDM.png}
        \end{subfigure}
    \end{figure}
    \vskip 5pt
    Dipartimento di Matematica “Tullio Levi-Civita”\\
    Università degli Studi di Padova\\
    \vskip 3pt
}

\date{July 23, 2020}
% \date{\today}

\begin{noheadline}
\begin{frame}\maketitle\end{frame}
\end{noheadline}

\setbeamertemplate{itemize items}[default]
\setbeamertemplate{itemize subitem}[circle]

\begin{frame}
    \frametitle{Overview} % Table of contents slide, comment this block out to remove it
    \tableofcontents % Throughout your presentation, if you choose to use \section{} and \subsection{} commands, these will automatically be printed on this slide as an overview of your presentation
\end{frame}

\section{Example}
\begin{frame}{Example}
hello!  % ok
àèòù    % ok
ì       % ERROR!
\end{frame}
\end{document}

编辑：您可以使用此模板仅通过写字母“ì”来重现错误： https://www.overleaf.com/latex/templates/armlab-latex-beamer-template/hndzfqkwrbyb

错误消息表明我在列表环境中使用了“item”，在内部垂直模式下使用了 \spacefactor，并且我漏掉了一个 $，而这一切都是为了一个“ì”。