# \underline and \underbar commands have change warning

I have two warnings telling me that "Command \underbar has changed." and "Command \underline has changed." but I don't get why is that so since I am not using these commands.

I have seen an explanation in this post but I am not using the package sectsty. Any help wuld be wellcome.

Below I am leaving a sample code of my preamble.

\documentclass[12pt]{article}

\usepackage{amssymb,
amsmath,
amsfonts,
eurosym,
geometry,
ulem,
graphicx,
caption,
color,
setspace,
sectsty,
comment,
footmisc,
caption,
% natbib,
%biblatex,
pdflscape,
array,
hyperref
}

\usepackage[latin1]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{lmodern}

% Package for drawings
\usepackage{tikz}

% Package for subcaption
\usepackage{subcaption}

% Options for biblatex package
\usepackage[
backend = biber,
bibencoding = latin1,
style = authoryear,
natbib,
]
{biblatex}
\normalem

\onehalfspacing
\newtheorem{theorem}{Theorem}
\newtheorem{corollary}[theorem]{Corollary}
\newtheorem{proposition}{Proposition}
\newenvironment{proof}[1][Proof]{\noindent\textbf{#1.} }{\ \rule{0.5em}{0.5em}}

\newtheorem{hyp}{Hypothesis}
\newtheorem{subhyp}{Hypothesis}[hyp]
\renewcommand{\thesubhyp}{\thehyp\alph{subhyp}}

\newcommand{\red}[1]{{\color{red} #1}}
\newcommand{\blue}[1]{{\color{blue} #1}}

\newcolumntype{L}[1]{>{\raggedright\let\newline\\arraybackslash\hspace{0pt}}m{#1}}
\newcolumntype{C}[1]{>{\centering\let\newline\\arraybackslash\hspace{0pt}}m{#1}}
\newcolumntype{R}[1]{>{\raggedleft\let\newline\\arraybackslash\hspace{0pt}}m{#1}}

\geometry{left=1.0in,right=1.0in,top=1.0in,bottom=1.0in}

\begin{document}
\end{document}

• The package sectsty, for some reasons, checks that the meaning of \underline and \underbar haven't changed from the kernel version; the kernel definition of those commands has changed, but the author of the package didn't update them. You are loading sectsty, by the way: this is what triggers the warnings. If you're not using its features, why do you load it? May 13 at 7:59
• \underline is TeX primitive. But if someone is using LaTeX then he/she can't be sure of anything:). May 13 at 8:31
• Sorry for the confusion, I was using a template and I took for granted that sectsty wasn't uploaded, I have removed it and now no warning appears. Thank you very much for your time May 14 at 8:34