# Why am I all of a sudden getting a Natbib warning?; all my citations are not working anymore

I'm using a LaTex template in Overleaf, I've been using it for months now and the citations always worked as I expected. Now all of a sudden I get a Natbib warning that all of my citations are undefined. My main.txt looks as follows:

\documentclass{clv3}
\usepackage{mathtools}
% Packages for template
\usepackage{todonotes}
\usepackage{amsmath}
\usepackage{hyperref}
\usepackage{booktabs}
\usepackage{multirow}
\usepackage{pgfplots}
\usepackage{standalone}
\usepackage{xcolor}
\usepackage{standalone}
\definecolor{darkblue}{rgb}{0, 0, 0.5}

\bibliographystyle{compling}

\input{meta-data.tex}
\pgfplotsset{compat=1.15}
\begin{document}
\input{front-page.tex}
\input{thesis.tex}
\end{document}


I'm new to working in LaTex and have no clue what I did to make this happen. Does anyone know how I can fix this?

This is the template I'm using (for information about compling style and cvl3): [https://www.overleaf.com/latex/templates/tilburg-university-csai-and-ds-and-s-masters-thesis-template/gybfzfwjmvjf][1]

UPDATE: Got in contact with Overleaf. This fixed my problem:

Creating a new file in the root directory called 'latexmkrc' (with no file extension), and inserting into it the following:

\$pdflatex = 'pdflatex --shell-escape %O %S; bibtex %R;'

• Please make this example self contained as we do not have access to the files you input. Also are you 100% sure that you do not have any compilation errors. – daleif Jan 8 at 14:12
• Off-topic: Don't load packages more than once (cf standalone), and do load hyperref last. – Mico Jan 8 at 14:17
• @daleif I added the template I'm using. Hope this is sufficient. – Mira Jan 8 at 15:29
• No the template is not sufficient. Quite probably you introduced an error somewhere. Check the blg-file and the log-file for errors. – Ulrike Fischer Jan 8 at 15:41
• Show the content of the blg-file. – Ulrike Fischer Jan 8 at 16:03