# Biblatex with biber backend results in undefined control sequences but not with bibtex backend [closed]

I use Texmaker (verion 3.4.1) and MikTeX 2.9 (which has been installed one week ago). Texmaker is configured to use biber: I replaced "bibtex %.aux" by "biber %". If I run LaTeX, then the file compiles without errors. The same goes for BiBTeX. But if I then run LaTeX again, then get error messages.

Here is a minimal working example:

\documentclass{article}
\usepackage[english]{babel}
\usepackage{csquotes}
\usepackage[backend=biber,style=authoryear-comp]{biblatex}
\begin{document}
\textcite{label}
\printbibliography
\end{document}


Here are the error messages:

! Undefined control sequence. ...c@refsection @entry@\blx@slist@name

l.39 \endentry

The control sequence at the end of the top line of your error message was never \def'ed. If you have misspelled it (e.g., \hobx'), typeI' and the correct spelling (e.g., I\hbox'). Otherwise just continue, and I'll forget about whatever was undefined.

! Undefined control sequence. ...c@refsection @entry@\blx@slist@name

l.39 \endentry

There are no error messages if I replace backend=biber with backend=bibtex.

How can I solve this problem?

-
This bug is fixed in the current development branch of biblatex. Install this branch to your local texmf tree and you can use biblatex. Here the link: sourceforge.net/projects/biblatex –  Marco Daniel Aug 9 '12 at 13:35
Before you install some development branch: Run the update manager of miktex. In case you have a multiuser setup: do it in user + admin mode. (biber + biblatex works fine for me with an up-to-date miktex). –  Ulrike Fischer Aug 9 '12 at 13:56
I'm sorry about this, I accidentally uploaded a broken biblatex 2.1 to TL originally. This might have found it's way into MikTeX. The 2.1 on SourceForge and in TL now is correct. –  PLK Aug 9 '12 at 17:12
i still have the same problem after running biber –  user17701 Aug 17 '12 at 13:24
Please do kpsewhich biblatex.sty` and paste here the top ten lines of the file which this returns. –  PLK Aug 19 '12 at 18:34