LaTeX.org

After contacting my administrator, it gave a quick fix (they can't update TeX easily). Just insert \string before : to tell Tex that this is not a macro.

Well,
I thought I posted a MWE. It still produces an error with my system, so this is probably a bug which has been corrected in the more recent versions of tex or babel but not on my version.

Unfortunately, I do not have administrator privilege on the computer which I am using (university ...

Hi,

I am getting an error when trying to compile the following code:

\documentclass{book}

\usepackage[frenchb,english]{babel}

\begin{document}

\section{The proof of Theorem \protect \ref{th:t2vla} }

\end{document}

The error is:

! Missing \endcsname inserted.
<to be read again>
\protect ...