[Tex/LaTex] Beamer Frankfurt theme undefined shading error

beamertikz-pgf

I updated MikTex and, since then, I have an "undefined shading" error when using the Frankfurt theme. I wonder what I am doing wrong. Many thanks for your help (any fix is welcome)!

Here is a minimal working example. 

\documentclass[xcolor=svgnames]{beamer}
\usetheme{Frankfurt}
\usecolortheme{crane}

\title{My title}


\author{Author}
\institute{Institute}

\date[]{Date}


\begin{document}

\begin{frame}
  \titlepage
\end{frame}


%==============================

\section{YY}
\subsection{YY1}

\begin{frame}{YY}

    \begin{itemize}
            \item XX
            \item XX

    \end{itemize}

\end{frame}

\end{document}

Compiling the file results in the following errors.

! Package pgf Error: Undefined shading "beamer@barshade".

See the pgf package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              

l.14 \begin{document}

? 

! Package pgf Error: Undefined shading "beamer@barshade".

See the pgf package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              

l.18 \end{frame}

? 
[1{C:/Users/studerm/AppData/Local/MiKTeX/2.9/pdftex/config/pdftex.map}]

! Package pgf Error: Undefined shading "beamer@aboveframetitle".

See the pgf package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              

l.34 \end{frame}

? 

! Package pgf Error: Undefined shading "beamer@belowframetitle".

See the pgf package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              

l.34 \end{frame}

? 

! Package pgf Error: Undefined shading "beamer@barshade".

See the pgf package documentation for explanation.
Type  H <return>  for immediate help.
 ...                                              

l.34 \end{frame}

Best Answer

Update

with pgf 3.1.3 it should work again.

Old answer

You are doing nothing wrong. pgf changed the handling of shadings, they are no longer globally defined and this breaks a number of beamer themes.

See https://github.com/pgf-tikz/pgf/issues/650 and https://github.com/josephwright/beamer/issues/536.

Related Question