# natbib error, "\providecommand\NAT@force@numbers{}\NAT@force@numbers"

During the last days I am really stressed because I face a problem with my References that I never had before. With the following, I try to generate my bibliography but I either get the error "\providecommand\NAT@force@numbers{}\NAT@force@numbers", or I get my document with question marks instead of bibliography names/dates.

Any ideas how to spot the issue which causes me this and fix it?

here are my two .bib files

I do not want to use natbib with numbers but with names and I do not understand the reason why I have this issue. I read similar issues but I can not spot any missing dates on my files which previously were fine and that is why I am confused.

P.S. I show you all the packages that I use in case something else causes the problem.

\RequirePackage{filecontents}
\documentclass[12pt,a4paper]{article}
\listfiles
\usepackage{amsthm}
\usepackage{titling}
\usepackage[utf8]{inputenc}
\usepackage{tcolorbox}
\usepackage{graphicx}
\usepackage{lipsum}
\usepackage{mwe}
\usepackage{subfig}
\usepackage{float}
%\usepackage{cite}
\usepackage[authoryear,round]{natbib}
%\usepackage[numbers]{natbib}
\usepackage{enumitem}
\usepackage{amsmath}
\usepackage{mathtools}
\usepackage{multicol}
\usepackage{stfloats}
\usepackage{authblk}
\usepackage{afterpage}
\usepackage[T1]{fontenc}
urlcolor  = blue,
citecolor = blue,
anchorcolor = blue]{hyperref}
\usepackage{amsfonts}
\usepackage{booktabs}
\usepackage{fancyhdr}
\usepackage{array}
\usepackage{pdflscape}
\usepackage{array,ragged2e,booktabs}
\usepackage{tikz}
\usepackage{longtable}
\usepackage{capt-of}
\usepackage{tabularx}
\usepackage{textcomp}
\usepackage{makecell}
\usepackage[british]{babel}
\usepackage[euler]{textgreek}
\usepackage{makecell}
\usepackage{xcolor,colortbl}

%\usepackage{dirtytalk}
%\usepackage[none]{hyphenat}
%\hyphenation{sy-ner-gi-stic}
%\usetikzlibrary{shapes.geometric, arrows}
\pagestyle{fancy}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%\fancyhf{}

\makeatletter
\def\thanks#1{\protected@xdef\@thanks{\@thanks
\protect\footnotetext{#1}}}
\makeatother
\renewcommand\tabularxcolumn[1]{m{#1}}
\definecolor{LightCyan}{rgb}{0.88,1,1}
\definecolor{Burntsienna}{rgb}{0.91,0.45,0.32}

\date{}

\newcolumntype{C}{>{$\displaystyle}c<{$}}
\bibliographystyle{apalike}
\setlist[enumerate]{label*=\arabic*.}
\begin{document}
\title{\vspace{-3.0cm}\rule{\textwidth}{1pt}\\title here \\\vspace{1.0cm}\rule{\textwidth}{1pt}\\{\Large Probation Report}}
\author{author here\thanks{department here}}

\maketitle
\newpage
\tableofcontents
\newpage
\renewcommand{\thesection}{\arabic{section}}

\section{bla bla}
bla bla bla bla  \citep{holling_resilience_1973,gunderson_ecological_2000} bla bla bla  \citep{gunderson_ecological_2000}. bla bla bla bla bla bla  \citep{achard_areas_2006, alkama_biophysical_2016, appenzeller_new_2015, bergeron_ecosystem_2017, berner_plant_2013,brown_once_2012, chapin_global_2004, forkel_trend_2013, forkel_codominant_2015, furyaev_effects_2001, lucht_terrestrial_2006, rydgren_disturbance_2004, jasinski_creation_2005, soja_climate-induced_2007, scheffer_thresholds_2012, williams_who_2011, young_climatic_2017, vygodskaya_ecosystems_2007, tanja_air_2003}.

\newpage
\section{References}
%\nocite{*}
\bibliography{fone,ftwo}
\newpage
\section{Supplementary material}

\end{document}

• Why are you using two bibliographystyle commands? (plainnat and apalike)? Nov 16, 2018 at 9:20
• @UlrikeFischer apologies, I do not, it is just a mistake here, I will edit my question. Thanks. Nov 16, 2018 at 9:32