Me gustaría eliminar el marco negro que aparece en la parte superior de cada página, como puedes ver en la imagen a continuación.
Me pregunto si no hubo un error en mi preámbulo. ¿Cómo podría solucionar eso? Este es mi MWE:
\documentclass{beamer}
\usetheme{default}
\usepackage{helvet}
\usepackage{framed,color}
\definecolor{shadecolor}{rgb}{0.74, 0.83, 0.9}
\useoutertheme[subsection=false]{smoothbars}
\usepackage[frenchb]{babel}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{helvet}
%%%%%%%%%%%%%%%%%paragraphes justifiés%%%%%
\usepackage{ragged2e}
\apptocmd{\frame}{}{\justifying}{} % Allow optional arguments after frame.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\setbeamertemplate{caption}[numbered]
\usepackage[labelsep=period]{caption}
%%%%%%%%%%%%%%%%%%%%%footline%%%%%%%%%%%%
\addtobeamertemplate{footnote}{}{\vspace{2ex}}
\setbeamertemplate{footline}[text line]{%
\parbox{\linewidth}{\vspace*{-8pt}Title
\hfill\insertshortsubtitle\hfill\strut\insertframenumber/\inserttotalframenumber}}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\setbeamertemplate{navigation symbols}{}
%%%%%%%%%%%%%%%%%NUMÉROTATION TOC%%%%%%%%
\setbeamertemplate{section in toc}{\hspace*{1em}\inserttocsectionnumber.~\inserttocsection\par}
\setbeamertemplate{subsection in toc}{\hspace*{2em}\inserttocsectionnumber.\inserttocsubsectionnumber.~\inserttocsubsection\par}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%\useinnertheme{circles}
\makeatletter
\patchcmd{\beamer@sectionintoc}{\vskip1.5em}{\vskip0.5em}{}{}
\makeatother
\usepackage{graphicx}
\usepackage{hyperref}
%%%%%%%%%%%%%%%%PLAN%%%%%%%%%%%%%%%%%%%%
\AtBeginSubsection[]
{
\begin{frame}<beamer>
\frametitle{Plan}
\tableofcontents[
currentsection,
sectionstyle=show/show,
subsectionstyle=show/shaded/hide
]
\end{frame}
}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\title[]{Title}
\subtitle[]{Subtitle}
\author[]{Author}
\institute[]{}
\date[] {}
\begin{document}
\frame{\titlepage}
\begin{frame}{Plan}
\tableofcontents
\end{frame}
\end{document}