# xkeyval error: 'defernums' undefined in families

Relative noob in LaTeX, and I'm trying to adapt an existing (public) template (with attribution) to my own needs, and the first step is gutting all the project specific code and setting up the environment so it builds. But, I'm getting this error on build (with texclipse, but same with from console) with no specific line number

Description Resource    Path    Location    Type
Package xkeyval Error: defernums' undefined in families blx@opt@pre'. \blx@processoptions (followed by: ) (Occurance: /usr/local/texlive/2011/texmf-dist/tex/latex/biblatex/biblatex.sty) thesis.tex  /mythesis   Unknown Texlipse Build Error


But I don't understand what's going wrong; this appears to be complaining about one of the texlive provided style files for biblatex... And I don't really want to be fiddling with those unless I know what I'm doing.

Anyone got any pointers?

The only section of my own custom sty file that deals with biblatex is

%% biblatex
\usepackage[
hyperref,backref,sortcites,
defernums=true,
date=short,
bibencoding=inputenc,
maxnames=3,
minnames=2,
firstinits=true,
sorting=nyt,
bibstyle=numeric,
citestyle=numeric-comp,
]{biblatex}
\def\bibfont{\small}
\bibliography{journals,phd,library}
\renewcommand\bibname{References}


For the full sty see here, with the sample case consisting of

\documentclass[11pt,a4paper]{memoir}
\usepackage{thesis-preamble}
%\includeonly{magnet-design}
\EndPreamble
\begin{document}
\title{helloworld}
\end{document}

-
The error is because the key defernums is used but not defined. You might not use all required options related to biblatex (just a guess) or use an old version of the package together with a package which relies on a newer version. Without seeing your code it is hard to tell what's wrong. I might try to create a minimal working example (MWE) by slowly removing all unrelated material until you narrow down the source of the issue. –  Martin Scharrer Oct 18 '11 at 8:33
Worked it out thanks to your hint –  Andrew Bolster Oct 18 '11 at 9:11

As of version 0.9b, Biblatex renamed the defernums option to defernumbers
Heh, as an anecdote: I was using omitnumbers=true in \printbibliography; biblatex complains about defernumbers. Then I add defernumbers=true to \printbibliography, I get: "! Package keyval Error: defernumbers undefined.". Then I finally realize defernumbers=true should sit in the preamble instead :) Cheers! –  sdaau May 24 '12 at 18:10