Une solution : `\let\YAD@supervisors@tabular\relax` `\let\YAD@supervisors@tabular\relax`.
La commande `\YAD@supervisors@tabular` est implicitement utilisée pour formater ses informations.
\documentclass{yathesis}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\begin{document}
\author{MAM}{Doe}
\supervisor{bla bla}{bla}
\comonitor{foor}{ faaat}
\makeatletter
\let\YAD@supervisors@tabular\relax
\makeatother
\maketitle%
\end{document}
