# Undefined control sequence \abx@aux@page

I am new LaTeX user (with Overleaf)

I have this kind of error and I have no idea how to fix it. My hypothesis is that I delete something in bibliography section, and now I don't know how to continue.

the error is

./0-complete.aux:43:
Undefined control sequence.
l.43 \abx@aux@page
{1}{25}
(no line number):
This is BibTeX, Version 0.99d (TeX Live 2015/Debian)
Capacity: max_strings=35307, hash_size=35307, hash_prime=30011
The top-level auxiliary file: 0-complete.aux
The style file: biblatex.bst
...


and the part related the code is:

\usepackage{natbib}
....
\bibliographystyle{agsm}
\begin{singlespace}
\pagestyle{plain}

\bibliography{Zotero}
\end{singlespace}


This is most likely caused by an outdated .aux file when you changed the bibliography style, or switched from biblatex to bibtex. You can try clearing the intermediate files on Overleaf, by clicking on the "recompile from scratch" option at the bottom of the error message window, and see if that clears the errors.