Miktex and beamer: Error: \beamer@endinputifotherversion

Question

I have downloaded MiKTeX (on Windows 10). The .tex files for papers and posters compile well but beamer does not work.

Here is the header of my .tex file:

\documentclass[10pt]{beamer}
%
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{fancybox}
\usepackage{amssymb}  %   MATH
\usepackage{amsmath}  %   MATH
\usepackage{latexsym} %   MATH
\usepackage{amsthm}   %   MATH
\usepackage[italian,english]{babel}
\usepackage{bm}         % per scrivere in grassetto i caratteri matematici
\usepackage{indentfirst}
\usepackage{color}
\usepackage{booktabs}
\usepackage{graphicx}
\usepackage{multimedia}
\usepackage{eurosym}
\usepackage{tikz}

I receive the following error message:

! Undefined control sequence. 
l.1 \beamer@endinputifotherversion
                                   {3.26pt}

How can this problem be fixed?

Joab Winkler

Answer 1

You've changed beamer versions and not deleted you auxiliary files. Older versions of beamer add \beamer@endinputifotherversion to the .nav and .toc files to check for version changes. This was removed in recent versions as it tends to cause more trouble than it fixes. As such, you can either

• Just press Return and let the run continue or
• Delete the .nav and .toc files

In either case, the issue will disappear at the next run.