# Package titlesec Warning: Non standard sectioning command \section

I have a problem with a package that I am not aware I am using ... Here is my main.tex

\RequirePackage{silence}
\WarningFilter{remreset}{The remreset package} %s shut up about obsolete package
% book example for classicthesis.sty
\documentclass[
% Replace twoside with oneside if you are printing your thesis on a single side
% of the paper, or for viewing on screen.
oneside,
%twoside,
11pt, a4paper,
footinclude=true,
cleardoublepage=empty
]{scrbook}

\usepackage{lipsum}
\usepackage{amsmath}
\usepackage{amsthm}
\usepackage{acronym}
\usepackage{listings} % ajouté pour corriger les deux erreurs de compilation
\usepackage{graphicx}
\usepackage{tabularx}
\usepackage[dvipsnames]{xcolor}
\usepackage{pdfpages}
\usepackage{hyperref}
\usepackage{microtype}
\hypersetup{
filecolor=magenta,
urlcolor=NavyBlue,
citecolor=NavyBlue,
}
\usepackage[english]{babel}
\usepackage[largesc]{newpxtext}
\useosf
\usepackage[utf8]{inputenc}
%\usepackage{wrapfig}
\usepackage{rotating}
\usepackage{epigraph}
\tolerance=1
\emergencystretch=\maxdimen
\hyphenpenalty=10000
\usepackage[font=small,skip=0pt]{caption}
\usepackage{listings}
\lstset{
basicstyle=\ttfamily,
columns=fullflexible,
frame=single,
breaklines=true,
postbreak=\mbox{\textcolor{red}{$\hookrightarrow$}\space},
}
\usepackage{soul} %to allow highlighting text that requires attention
\newcommand{\hash}[1]{{\ttfamily\seqsplit{#1}}}
\begin{document}
\input{titlepage.tex}
\input{first.tex}
%\include{FrontBackMatter/abstract}
%\include{FrontBackMatter/dedication}
%\include{FrontBackMatter/acknowledgements}
%\include{FrontBackMatter/declaration}

\include{FrontBackMatter/contents}

\chapter{Introduction}
\input{chapter1.tex}

\chapter{Genome assembly}
\input{chapter2.tex}

\chapter{Mutation accumulation}
\input{chapter3.tex}

\chapter{Perspectives}
\input{chapter4.tex}

\chapter{Bibliography}
\bibliographystyle{naturemag}
\bibliography{bibliography}
\chapter{annexes - publications}
\input{annexes.tex}
\end{document}


The compilation returns

Package titlesec Warning: Non standard sectioning command \section detected. Using default spacing and no format.


What is that titlesec package? I am not loading it. I am just using \section and \subsection throughout the document.

Any idea?

Thanks a lot, that would be hugely appreciated.

EDIT: here is the miminal example

Package titlesec Warning: Non standard sectioning command \section detected. Using default spacing and no format.

Is this actually a harmless warning? Or does it run the risk to cause other problems?

\RequirePackage{silence}
\WarningFilter{remreset}{The remreset package}
\documentclass[
% Replace twoside with oneside if you are printing your thesis on a single side
% of the paper, or for viewing on screen.
oneside,
%twoside,
11pt, a4paper,
footinclude=true,
cleardoublepage=empty
]{scrbook}

\usepackage{lipsum}
\usepackage{amsmath}
\usepackage{amsthm}
\usepackage{acronym}
\usepackage{listings}
\usepackage{graphicx}
\usepackage{tabularx}
\usepackage[dvipsnames]{xcolor}
\usepackage{pdfpages}
\usepackage{hyperref}
\usepackage{microtype}
\hypersetup{
filecolor=magenta,
urlcolor=NavyBlue,
citecolor=NavyBlue,
}
\usepackage[english]{babel}
\usepackage[largesc]{newpxtext}
\useosf
\usepackage[utf8]{inputenc}
%\usepackage{wrapfig}
\usepackage{rotating}
\usepackage{epigraph}
\tolerance=1
\emergencystretch=\maxdimen
\hyphenpenalty=10000
\usepackage[font=small,skip=0pt]{caption}
\usepackage{listings}
\lstset{
basicstyle=\ttfamily,
columns=fullflexible,
frame=single,
breaklines=true,
postbreak=\mbox{\textcolor{red}{$\hookrightarrow$}\space},
}
\usepackage{soul} %to allow highlighting text that requires attention
\newcommand{\hash}[1]{{\ttfamily\seqsplit{#1}}}
\begin{document}

\chapter{Introduction}
\section{youpla boum}
blablabal

\end{document}

• titlesec is loaded by classicthesis. KOMA-Script and titlesec are not working well together. Maybe you can find a fix here: tex.stackexchange.com/questions/511049/… – DG' Oct 6 '20 at 9:23
• waw thanks you. Though I have to admit it's a bit difficult for my level of understanding of LateX. I will try my best. – Alessandro Oct 6 '20 at 9:33
• classicthesis has some design flaws, which the author acknowledges in the package documentation (he is planning a e-design). However we cannot help you with your code, since we don't have the files you are including. Please prepare a minimal working example (MWE) – DG' Oct 6 '20 at 9:43

classicthesis has some design flaws, especially using KOMA-Script and titlesec, which the author acknowledges in the package documentation (he is planning a e-design):