Este é o meu preâmbulo, tentei várias coisas, incluindo executá-lo através do pdflatex (sem fontspec etc.) e seguir a documentação corretamente, até onde posso dizer (embora esteja claro que não estou). Eu usei TeXworks e TexStudio.
\documentclass[12pt]{article}
\usepackage[a4paper]{geometry}
\usepackage{fontspec}
\linespread{1.5}
\setmainfont{Times New Roman}
\usepackage{siunitx}
\title{a title}
\author{a name}
\newpage
\setcounter{page}{1}
\bibliography{essay}
\bibliographystyle{apalike}
\begin{document}
Este é o log quando tento compilar
Missing \begin{document}. \begin{thebibliography}{}
Missing \begin{document}. \begin{thebibliography}{}
Empty `thebibliography' environment
Citation `Pyne05' on page 2 undefined
Citation `loturco15' on page 2 undefined
Citation `till15' on page 2 undefined
Citation `Haguenauer05' on page 2 undefined
Citation `baptista16' on page 2 undefined
Citation `atkinson98' on page 2 undefined
Citation `atkinson98' on page 2 undefined
Citation `safrit' on page 2 undefined
Citation `buckthorpe12' on page 2 undefined
Citation `leard' on page 2 undefined
Citation `comyns23' on page 2 undefined
Citation `buckthorpe12' on page 2 undefined
Citation `buckthorpe12' on page 2 undefined
Citation `klavora' on page 2 undefined
Citation `buckthorpe12' on page 2 undefined
Citation `leard' on page 2 undefined
Citation `buckthorpe12' on page 2 undefined
Citation `leard' on page 2 undefined
Citation `comyns23' on page 2 undefined
Citation `buckthorpe12' on page 2 undefined
Citation `leard' on page 2 undefined
Citation `comyns23' on page 2 undefined
Citation `buckthorpe12' on page 2 undefined
Citation `comyns23' on page 2 undefined
Citation `buckthorpe12' on page 2 undefined
Citation `leard' on page 2 undefined
Citation `buckthorpe12' on page 2 undefined
Citation `comyns23' on page 2 undefined
Citation `leard' on page 2 undefined
Underfull \hbox (badness 10000) in paragraph
Underfull \hbox (badness 10000) in paragraph
Underfull \hbox (badness 10000) in paragraph
Underfull \hbox (badness 10000) in paragraph
Underfull \hbox (badness 10000) in paragraph
Underfull \hbox (badness 10000) in paragraph
There were undefined references.
Não tenho ideia de por onde começar com o que está errado, depois de ler vários artigos sobre solução de problemas. Não consigo encontrar nada que seja óbvio o suficiente para eu perceber.