I have to prepare a paper using the PoS class version provided by the conference organizers, and available via link: PoS for TWEPP 2018

However, I needed also to use the hyperref packet to provide clickable links in the produced PDF. Unfortunately, when hyperref packed is used, the pdflatex is not able to process the tex file, and the errors about not defined control sequences are produced:

! Undefined control sequence.
<recently read> \Hy@colorlink 
l.25 \begin{document}
! Undefined control sequence.
\close@pdflink ->\Hy@endcolorlink 
                            \Hy@VerboseLinkStop \pdfendlink 
l.25 \begin{document}
! Undefined control sequence.
<recently read> \Hy@colorlink 
l.25 \begin{document}

It looks like the PoS class breaks the definitions put into the \AtBeginDocument by hyperref. What is the cause of the problem, and how can I cure it?

Below is the example allowing to reproduce the problem (based on original skeleton.tex provided by the organizers). Please note that to compile it with pdflatex, you also need the PoSlogo.pdf file. If you replace the \usepackage{hyperref} with \usepackage{url}, everything works fine...

% Please make sure you insert your
% data according to the instructions in PoSauthmanual.pdf
\title{Contribution title}
\ShortTitle{Short Title for header}
\author{\speaker{First Author}\thanks{A footnote may follow.}\\
        Author affiliation\\
        E-mail: \email{author@email}}
\FullConference{Topical Workshop on Electronics for Particle Physics (TWEPP2018)\\
17-21 September 2018\\
    Antwerp, Belgium}

\section{Sample section}
 Just a small link: \href{https://stackexchange.com}{https://stackexchange.com}
  • 1
    The link is clickable without loading hyperref. So why do you think you need it? Oct 4, 2018 at 7:50
  • Yes, indeed. It is my stupid mistake that I tried to use hyperref before I checked if the class supports hyperlinks itself. Should I withdraw my question to avoid confusion?
    – wzab
    Oct 4, 2018 at 8:01
  • 1
    no other people may have the same confusion, you or @campa or Ulrike should post an answer I think:-) Oct 4, 2018 at 8:42

1 Answer 1


The link is clickable without loading hyperref.

The class has its own implemention of \href (incompatible with hyperref).

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