# Overleaf natbibapa citations break overnight

At first I thought I had accidentally broken something, but this is repeatable.

Here's the basic version of my paper:

\documentclass[12pt]{article}
\usepackage[natbibapa]{apacite}
\usepackage{fullpage}

\begin{document}
%content
\citep{Sibert2018}
%content
\bibliographystyle{apacite}
\end{document}


And if I leave this alone overnight, it will be broken in the morning, and I'll get an error message: "Citation %s undefined on page %i on input line %i."

If I clear the cache files, same error. If I delete and re-upload my bib file, same error.

HOWEVER, if I delete all my content and citations, compile and get an "empty thebibliography" error, the next time I compile, all my citations will behave.

My current workaround is to delete all the lines about color and recompile. This works.

Why??? How can I avoid having to perform such a silly workaround?

• This is certainly unusual behaviour. Can you also reproduce the issue in the small 'basic' version of your paper? Can you come up with an example document and an example .bib file that consistently reproduces the issue? (Please see tex.meta.stackexchange.com/q/228/35864 and tex.meta.stackexchange.com/q/4407/35864). Can you show us the complete .log and .blg file of the failing runs? (On Overleaf v2 you can get them the same way you obtain the .bbl file: tex.stackexchange.com/q/462314/35864, for v1 see tex.stackexchange.com/q/388656/35864) – moewe Nov 30 '18 at 14:29
• Perhaps check that your project's main file is indeed set to the correct .tex file? You can click on the Overleaf menu icon above the file list panel, and check the "Main document" setting. – LianTze Lim Nov 30 '18 at 15:33
• Mhh, the .log file looks unsuspicious enough. It looks exactly like I would expect if BibTeX could or did not run. In particular there is no error or warning unrelated to undefined citations. If there is no .blg file that is very suspicious: BibTeX should be run on this document and there should be at least something in the .blg file even if things went wrong quickly. I'm afraid there is not a lot we can do without a .blg file or a code example that consistently reproduces the issue. ... – moewe Dec 2 '18 at 7:16
• ... You could try contacting the Overleaf team about this. Strictly speaking it may not be their job to fix errors in your documents for you, but they are usually very responsive and eager to help and they can access more information about your project than we. – moewe Dec 2 '18 at 7:17
• I will keep trying to produce a minimal example, but it take several hours per trial, because of the nature of the error. Will edit question if I get one or if I get something from overleafe support – Crewis Dec 2 '18 at 17:07