\usepackage{caption} with beamer gives Missing number treated as zero

Question

If I use the caption package with beamer frames, I get a 'missing number treated as zero'.

The following compiles with texlive, but if I uncomment the \usepackage{caption} line, I get the error.

\documentclass[10pt]{beamer}
\usetheme{metropolis}
\usepackage{appendixnumberbeamer}
% \usepackage{caption}
\title{Error}
\author{Author}
\institute{Stack Overflow}
\begin{document}
\maketitle
\begin{frame} \frametitle{Introduction}
\begin{columns}
    \begin{column}{0.5\textwidth}
        \begin{figure}
            \includegraphics[width=.9\linewidth]{example-image-duck}
            \caption{Duck\footnote[frame]{Duck Duck}}
        \end{figure}
    \end{column}
    \begin{column}{0.5\textwidth}
        \begin{figure}
            \includegraphics[width=.9\linewidth]{example-image-duck}
            \caption{Duck\footnote[frame]{Duck Duck}}
        \end{figure}
    \end{column}
\end{columns}
\end{frame}
\end{document}

Hello and welcome. The error is from the [frame] option added to the macro \footnote[frame]{}. Removing this option will make it work : \caption{Duck\footnote{Duck Duck}}. Where did you get this [frame] option? — AndréC, Jul 19 '20 at 05:52
I think in general beamer is incompatible with caption. beamer already provides caption-related templates to control style of \caption, see beamer manual, sec. 12.6. Hence you can avoid loading caption by make use of those beamer caption templates. — muzimuzhi Z, Jul 19 '20 at 05:55
@AndréC \footnote[frame] is supported by beamer to indicate "this footnote should be typeset at the bottom of the frame", see beamer manual, sec. 12.12. Furthermore, although no errors, using \caption{Duck \footnote{Duck Duck}} produces wrong output, in which the width of column is wider than expected. From beamer issue #268, Incompatibility of beamer with caption package, it seems the compatibility issue is never solved. — muzimuzhi Z, Jul 19 '20 at 06:00
On the caption side, it do fixed compatibility reported issues with beamer, see here. So if one can reduce the problem to be caption-related, an issue to https://gitlab.com/axelsommerfeldt/caption/-/issues is welcome. @AndréC I checked again, the too-wide column issue is reproducible even without caption. Sorry for my mis-judgement. — muzimuzhi Z, Jul 19 '20 at 06:17
I wanted my captions to appear without the labels, so I was using caption package. I removed it and set \setbeamertemplate{caption}{\raggedright\insertcaption\par} as mentioned in this question: https://tex.stackexchange.com/a/82460/220753
Thank you for your replies. — oponkork, Jul 19 '20 at 06:38
This is an compatibility issue, and I've reported to caption. See https://gitlab.com/axelsommerfeldt/caption/-/issues/84. — muzimuzhi Z, Jul 19 '20 at 07:09
@oponkork Or you can use \caption{Dock\footnotemark} and then \footnotetext[1]{Duck Duck} outside of columns environment. — muzimuzhi Z, Jul 19 '20 at 07:10

muzimuzhi Z · Answer 1 · 2020-07-22T22:03:41.623

Some updates:

Thanks to Axel Sommerfeldt, the author of caption, this compatibility issue has been fixed in caption 2020-07-20, and the update is already installable in TeX Live. MiKTeX users might need to wait.

This update even allows the direct use of \footnote in multi-line \caption, which will produces two copies of footnote text at the bottom of frame in plain beamer.

\documentclass[10pt]{beamer}
\usetheme{metropolis}
\usepackage{appendixnumberbeamer}
\usepackage{caption}
\begin{document}
\begin{frame} \frametitle{Introduction}
\begin{columns}[t]
    \begin{column}{0.5\textwidth}
        \begin{figure}
            \includegraphics[width=.9\linewidth]{example-image}
            \caption{Duck\footnote[frame]{Duck Duck}}
        \end{figure}
    \end{column}
    \begin{column}{0.5\textwidth}
        \begin{figure}
            \includegraphics[width=.9\linewidth]{example-image}
            \caption{Duck Duck Duck Duck Duck Duck\footnote[frame]{Duck Duck}}
        \end{figure}
    \end{column}
\end{columns}
\end{frame}
\end{document}

\usepackage{caption} with beamer gives Missing number treated as zero

1 Answers1