As of today, I have not been able to build any documents using the biblatex-chicago class. MWE follows:

\usepackage[nopar]{lipsum} % for dummy text
Author = {Ferdinand de Saussure},
Origyear = {1916},
Publisher = {Payot},
Title = {Cours de Linguistique G{\'e}n{\'e}rale},
Year = {1995}}




Running latexmk -cd -e -f -pdf -interaction=nonstopmode -synctex=1 myfile.tex

produces the following error:

 Undefined control sequence.
\cms@choose ->\ifblx@load@version@one 
                                      nty\else cms\fi 
l.40 \begin{document}

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'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

The MWE works without problems if I substitute biblatex for biblatex-chicago.

Any ideas? Thank you.

  • This compiles fine for me on a TL 2015 system. Have you deleted all your aux files and tried again? What happens when you run the pieces separately, i,e., run pdflatex then biber then pdflatex?
    – Alan Munn
    Mar 10, 2016 at 23:12
  • Deleting all temp files (including .aux) does not resolve the issue. Running manually breaks at step one (pdflatex), with the same error message. Mar 10, 2016 at 23:21
  • It seems due to the new biblatex version. :(
    – egreg
    Mar 10, 2016 at 23:25
  • @egreg Yes, I just updated and now it fails for me too.
    – Alan Munn
    Mar 10, 2016 at 23:31
  • 1
    Please be aware that the new biblatex version has changed the name formatting commands in a way that will cause no errors with biblatex-chicago, but some name definitions will be ignored silently. Do check your output for CMS compliance.
    – moewe
    Mar 16, 2016 at 10:26

3 Answers 3


The biblatex-chicago package has been updated to version 0.9.9h 2016-03-22.

According to the package documentation, this update specifically addresses incompatibilities with biblatex, version 3.3.

The biblatex-chicago package is now available through CTAN: http://www.ctan.org/pkg/biblatex-chicago


This is caused by a change in the biblatex test for an old system. The previous conditional was called \ifblx@load@version@one and is used in the biblatex-chicago style. The new conditional is called \ifblx@load@version@legacy. You can temporarily solve the problem in the following way by adding the following to your preamble, after loading biblatex.


A more general solution is given in Herbert's answer:


But a long term solution to the problem will be a fix to biblatex-chicago.


Write into the preamble:


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