How to fix a natbib apacite citation when it displays the wrong year?

Question

I would like to cite something so that it comes up as

Something important has been shown (author, 2000; 2006).

Although, I do not care about the separator between 2000 and 2006 (the semicolon was just used as an example).

When I compile my document, I get

Something important has been shown (author, 2000, 0).

Citation1 is an article (published in 2000) and citation2 is a book (published in 2006).

The code I currently use looks approximately like this:

\RequirePackage{filecontents}
\begin{filecontents}{bibliography.bib}
@book{doyle2006making,
  title={Making war and building peace: United Nations peace operations},
  author={Doyle, Michael W and Sambanis, Nicholas},
  year={2006},
  publisher={Princeton University Press}
}

@article{doyle2000international,
  title={International peacebuilding: A theoretical and quantitative analysis},
  author={Doyle, Michael W and Sambanis, Nicholas},
  journal={American political science review},
  volume={94},
  number={4},
  pages={779--801},
  year={2000},
  publisher={Cambridge University Press}
}
\end{filecontents}

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[natbibapa]{apacite}
\usepackage[super]{nth}
\usepackage{graphicx, floatpag, caption}
\newcommand\textlcsc[1]{\textsc{\MakeLowercase{#1}}}
\usepackage{bibentry}
\nobibliography*
\usepackage[hyphens]{url}
\usepackage{float}
\usepackage{rotating}
\usepackage{pdflscape}



\begin{document}

Something important has been shown \citep{citation1, citation2}.

\newpage
\bibliographystyle{apalike}
\bibliography{bibliography.bib}
\end{document}

Answer 1

The apacite package can only be used with the apacite bibliography style, and you are loading the apalike style, so to fix your problem you need to use:

\bibliographystyle{apacite}

As moewe notes in the comments, the syntax of the \bibliography command requires a .bib file name without the .bib extension, and you're just lucky if this works. So if your .bib file is named mybib.bib you should use:

\bibliography{mybib}