\titlecontents{section}[0em]{}{\thecontentslabel\quad\ul}{\ul}{\hfill\thecontentspage}
is incompatible with
\usepackage{hyperref}
For more context, cf. [User Bernard's answer](http://tex.stackexchange.com/a/311319/67761) in [Incompatibility of \setcounter{secnumdepth}{0} with \titlecontents{section}{\thecontentslabel\quad}{\underline}{}{\hfill\thecontentspage}](http://tex.stackexchange.com/questions/311314/).