title: subfig package gives error "Undefined control sequence. \begin{document}" error in beamer
body: <p>I’m getting an error with loading subfig package for beamer document class. It gives an error “Undefined control sequence. \begin{document}”.  </p>
  
  <p>Here is a MWE:</p>
  
  <pre><code>\documentclass{beamer}
  \usepackage{subfig}
  
  \begin{document}
  
  \begin{frame}{MWE}
  \end{frame}
  
  \end{document}
  </code></pre>
  
  <p>The code from which I made this MWE used to work fine a few months ago. </p>