I am currently writing my master's thesis using TeX Live and Texmaker and have suddenly run into an "undefined control sequence" that points to the line


in my preamble. However, this error only surfaces on the second run of pdflatex when all .aux-files etc. are deleted in the respective folder. With pre-existing files, this happens already on the first run.

My current preamble (shortened):

\include{TitlePage} %removed several chapters of text

The errors I am receiving are several lines long, thus I have added only the first two:

! Undefined control sequence.
\blx@theformat #1#2#3#4#5#6#7#8->\nameparts
{#1}\ifthenelse {\value {listcou...
l.48 ...raphy[heading=bibintoc,title={References}]
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.
! Undefined control sequence.
<argument> ...artprefix \namepartfamily }\ifempty
{\namepartprefix }{}{\mkbi...
l.48 ...raphy[heading=bibintoc,title={References}]
The control sequence ...

I have been looking for an answer for several hours, but cannot seem to find the root cause of this problem. Any help would be much appreciated!

  • Try writing it without the curly brackets, as in title=References. – Alenanno Mar 6 '16 at 20:04
  • Thanks for the hint, but the errors are the same after removing the curly brackets. – Andy Mar 6 '16 at 20:27
  • 3
    In version 3.3 of biblatex the name handling was substantially revised. biblatex-apa v 6.8 already uses the new name handling and has been available on CTAN (and MikTeX) for a few days now. biblatex 3.3, however, has only just arrived at CTAN, so it might take another day or so to propagate to all mirrors and TeX Live and MikTeX. – moewe Mar 6 '16 at 20:50
  • 2
    I just wanted to confirm that it is indeed working again with the latest updated packages. Thanks everyone for your help! – Andy Mar 18 '16 at 13:03
  • 5
    I'm voting to close this question as off-topic because it was caused by a temporary version mismatch on CTAN that has since been resolved, the issue is solved by an update (see comment above). – moewe May 12 '16 at 7:30