Why is the prefix in my citation not working?

When I try to make a prefix, it breaks the command. I have tried both the \citep, \citet and the \cite commands. I have also tried looking at the Babel files, and changing the < and > to << and >> in the commands:

\declare@shorthand{danish}{"<}{\textormath{\guillemotleft}{\mbox{\guillemotleft}}} \declare@shorthand{danish}{">}{\textormath{\guillemotright}{\mbox{\guillemotright}}}

But that did not work. Postfixes works fine.

\documentclass[11pt]{memoir}
\usepackage[danish]{babel}
\renewcommand{\danishhyphenmins}{22}
\usepackage[natbibapa]{apacite}

\begin{document}
\section{Citations}
\citep<The prefix is not working>[Postfix works fine]{smiths}

\bibliographystyle{apacite}
\bibliography{refs}
\end{document}

@article{smiths,
author = {Smith, A.},
journal = {Journal of Apacite},
number = {1},
pages = {24305--36811},
title = {{How do I prefix?}},
volume = {1},
year = {2014}
}