# Biblatex.sty not found error while using Travis (from an Overleaf document)

I have been using Overleaf for all latex documents and I want to compile them using Travis. I'm getting stuck at the biblatex.sty file and despite downloading one from https://ctan.org/tex-archive/macros/latex/contrib/biblatex?lang=en it shows the following error:

! Missing \endcsname inserted.
<to be read again>
\blx@datamodel@constant@optiondatatypes
l.6741 ...odel@constant@optiondatatypes\endcsname}

?


If I don't use an external .bib file and add citations using \begin{thebibliography}...\end{bibliography}, the Travis compilation does not show any error. The .bib file on Overleaf also compiles properly so I don't know what I'm missing here. I have tried commenting this line out and I have also tried to remove the \endcsname part of the code but it's still showing errors.

• biblatex is found, you get an error from it. This can have many reasons, beside other version mismatches, if you use a biblatex version not fitting the biber version. – Ulrike Fischer Jun 11 at 8:48
• Usually it is a bad idea to manually download .sty files from CTAN. It would be better to install packages via your TeX distribution (tlmgr). But it is almost impossible to investigate this any further without an example document that reproduces the issue (with as little code as possible) and the complete .log file of the failing run. – moewe Jun 11 at 8:53
• The thing is that I'm using overleaf and I haven't been able to find those packages. – Bhavini Jun 11 at 9:17
• Hello @Bhavini, Tom from Overleaf support here. Overleaf updates it's TeX Live version in a regular cycle with releases in Q3 each year. For stability and compatibility reasons, we only update packages for clear bugs in the existing images. This means that if you need some functionality that's newer than biblatex v3.14, that's a problem, because while you can update the biblatex files by uploading them into the project, you can't update biber, and as Ulrike points out this causes issues. Sorry for the limitation. – yo' Jun 11 at 9:50
• Because we don't know how you installed TeX on your Travis system we can't tell you how you can install or update biblatex and friends there. If you installed a vanilla TeX live (tex.stackexchange.com/q/1092/35864), you would use tlmgr install biblatex biber and tlmgr update --self --all. If you installed TeX live via apt-get you might be stuck with an ancient version of TeX Live. – moewe Jun 12 at 10:07