How to get uppercase section name in beamer with \insertsection?

I want to have a beamer presentation with a slide with the section name.

This does what I need, as a MWE, and it works:

\documentclass{beamer}
\usepackage[utf8]{inputenc}

\AtBeginSection[]{
\begin{frame}
\centering\Huge
--- \insertsection\ ---
\end{frame}
}

\begin{document}

\section{First}
\begin{frame}
This is a first
\end{frame}

\section{Second}
\begin{frame}
This is a second
\end{frame}

\end{document}


But I want to show the section name in uppercase, but if I try the following modification, I get tons of errors.

\AtBeginSection[]{
\begin{frame}
\centering\Huge
--- \MakeUppercase{\insertsection} ---
\end{frame}
}


These are the first lines of the errors:

Undefined control sequence. \section{First}
Argument of \beamerx@\hyperlink has an extra }. \section{First}
Paragraph ended before \beamerx@\hyperlink was complete. \section{First}
Undefined control sequence. \section{First}
Use of \beamer@foundspec doesn't match its definition. \section{First}
Undefined control sequence. \section{First}
Undefined control sequence. \section{First}
Argument of \reserved@a has an extra }. \section{First}
--- cut ---


Any tips how to get the uppercase here? I'm really lost...

Edit

Everthing ok after updating to v3.50.

• Actually \MakeUppercase{\insertsection} works fine for me. Which version of beamer do you have? – user36296 Apr 19 '18 at 15:01
• It says \def\beamer@version{3.36}. Is that what you wanted? – Jander Apr 19 '18 at 15:08
• @Jader Update! ~~~~~~~~~~~ – user36296 Apr 19 '18 at 15:09
• With v3.50 it works fine. – user36296 Apr 19 '18 at 15:13
• Updating to 3.50 solved the problem! Thanks. – Jander Apr 20 '18 at 11:08