Biber/BibLaTeX \printbibliography causes "undefined control sequence" in the proceeding line

Question

I'm using biblatex with biber as the backend to write my document. Without \printbibliography, all the citations work perfectly well, and appear in the document, so I assume that my bibliography.bib file is fine. The problem comes, however, when I include the line \printbibliography at the end of my document (just before \end{document}): suddenly every time I try to compile I get "undefined control sequence" referencing whatever line is after \printbibliography.

Following suggestions elsewhere on the internet, I combed my document for "smart" quotation marks, and other weird characters, but there aren't any. My citations are downloaded from ADSABS, with the occasional @ONLINE resource, too. As I said, though, all the references work fine, it's just the \printbibliography command that bails.

To illustrate (I'm not going to paste the entire document here unless someone thinks it will be helpful):

\usepackage[style=authoryear-icomp,sorting=anyt]{biblatex}
\addbibresource{bibliography.bib}

...

\printbibliography

Answer 1

I had a similar issue. I pinpointed the problem to be in the .bib file. My advice is to carefully examine your .bib file for possible ambiguous syntax. In my case, the problematic syntax was:

...
title = {A 70~kW stationary fuel cell system},
...

The undefined control sequence issue was resolved, when this was changed to the following (i.e., the expression with the tilde was enclosed in the curly braces):

...
title = {A {70~kW} stationary fuel cell system},
...

A short comment (maybe someone will find it useful). In my case, the issue occurred after the matlab-prettifier package was loaded, which also loads the listings package. Until these packages were load, I had experienced no issues whatsoever.

Answer 2

The problem in the bibliography.bib file (https://gist.github.com/gfarrell/9892791) was an undefined control sequence after all: ADSABS inserts control sequences for journals like \aap.

Removing these and replacing them with the actual journal names fixes the problem.

(If anyone knows a package that defines all of these it would be quite helpful).

Answer 3

In my case it was a $\mathsemicolon$ in booktitle in the automatically imported entry using jabref.

fixed it, re-run biber, recompiled and works now.

Answer 4

I had the same problem from a bibtex entry which was imported by DOI (using Jabref).

In one article's title there was a {\textquotesingle} included. This caused biblatex to break.

After removing it, the compilation worked again.

Answer 5

Here is how I methodically debugged and fixed the issue.

1. The input file mentioned before the line number in the error message was the .bbl file, so I opened the .bbl file in my editor, and navigated to that line number.
2. I removed that entry (from \entry to \endentry) from the .bbl file. After that I could run LaTeX without errors, so I knew that the specific entry was the error cause.
3. I started removing elements from the specific entry, until I found an offending character, which I then corrected, first in the .bbl file to validate my hypothesis that this was the cause and then in the .bib file to fix the root cause.

In my case the .bib file contained the author name Agust{\'}{\i}n, which generated an invalid Unicode character. Changing it to Agust{\'}{i}n fixed the problem.

Answer 6

It is also worth carefully examining the latex console output. In my case, it mentioned a "misplaced alignment character &" in "IEEE Robotics & Automation Magazine". Changing the offending & to & in the bibliography fixed the issue.