\documentclass{interact}
\usepackage{epstopdf}% To incorporate .eps illustrations using PDFLaTeX, etc.
\usepackage{subfig}% Support for small, `sub' figures and tables
%\usepackage[nolists,tablesfirst]{endfloat}% To `separate' figures and tables
%from text if required
%\usepackage[doublespacing]{setspace}% To produce a `double spaced' document if
%required
%\setlength\parindent{24pt}% To increase paragraph indentation when line spacing
%is doubled
\usepackage[longnamesfirst,sort,comma,authoryear]{natbib}% Citation support
%using natbib.sty
\bibpunct[, ]{(}{)}{;}{a}{,}{,}% Citation support using natbib.sty
\renewcommand\bibfont{\fontsize{10}{12}\selectfont}% To set the list of
%references in 10 point font using natbib.sty
%\usepackage[natbibapa,nodoi]{apacite}% Citation support using apacite.sty.
%Commands using natbib.sty MUST be deactivated first!
%\setlength\bibhang{12pt}% To set the indentation in the list of references
%using apacite.sty. Commands using natbib.sty MUST be deactivated first!
%\renewcommand\bibliographytypesize{\fontsize{10}{12}\selectfont}% To set the
%list of references in 10 point font using apacite.sty. Commands using
%natbib.sty
%\MUST be deactivated first!
\theoremstyle{plain}% Theorem-like structures provided by amsthm.sty
\newtheorem{theorem}{Theorem}[section]
\newtheorem{lemma}[theorem]{Lemma}
\newtheorem{corollary}[theorem]{Corollary}
\newtheorem{proposition}[theorem]{Proposition}
\theoremstyle{definition}
\newtheorem{definition}[theorem]{Definition}
\newtheorem{example}[theorem]{Example}
\theoremstyle{remark}
\newtheorem{remark}{Remark}
\newtheorem{notation}{Notation}
\usepackage{amsmath}
\usepackage{hyperref}
\usepackage{makecell}
\usepackage{graphicx}
\usepackage{longtable}
\usepackage{supertabular}
\usepackage{morefloats}
\usepackage{tablefootnote}
\usepackage[final]{pdfpages}
\usepackage{import}
\usepackage{filecontents}
\usepackage{multirow}
\usepackage{booktabs}
\usepackage{siunitx}
\usepackage{soul}
\usepackage{textcomp}
\usepackage{threeparttable}
\usepackage[natbibapa,nodoi]{apacite}
\setlength\bibhang{12pt}
\renewcommand\bibliographytypesize{\fontsize{10}{12}\selectfont}
%\usepackage{cite}
\renewcommand{\bibname}{References}
\begin{document}
\bibliographystyle{apacite}
\bibliography{thesis}
\end{document}
答案1
只需进行这些更改，就不会再出现任何错误：
首先摆脱了你的documentclass（替换为article，但没有要求这样做......只是不能 - 不想 - 搜索它）。 我还必须摆脱（注释掉）`teoremstyle`......但如果它在那里定义，你可以使用它。
第二去掉了\usepackage{epstopdf}...如果你真的需要它，就添加它，但graphicx在它之前添加或其他东西。
第三次加载apacite之前natbib要清除一些剩余的错误。
根据这篇文章，第四个：https://tex.stackexchange.com/a/263800/120578
我必须natbib在加载时从包中删除选项。（考虑不要混合包，因为没有必要这样做 - 阅读那篇文章 -）
以下代码（经过上述更改）不会出现错误。
\documentclass{article}
%\usepackage{epstopdf}% To incorporate .eps illustrations using PDFLaTeX, etc.
\usepackage{subfig}% Support for small, `sub' figures and tables
%\usepackage[nolists,tablesfirst]{endfloat}% To `separate' figures and tables
%from text if required
%\usepackage[doublespacing]{setspace}% To produce a `double spaced' document if
%required
%\setlength\parindent{24pt}% To increase paragraph indentation when line spacing
%is doubled
\usepackage[natbibapa,nodoi]{apacite}
\usepackage{natbib}% Citation support
%using natbib.sty
\bibpunct[, ]{(}{)}{;}{a}{,}{,}% Citation support using natbib.sty
\renewcommand\bibfont{\fontsize{10}{12}\selectfont}% To set the list of
%references in 10 point font using natbib.sty
%\usepackage[natbibapa,nodoi]{apacite}% Citation support using apacite.sty.
%Commands using natbib.sty MUST be deactivated first!
%\setlength\bibhang{12pt}% To set the indentation in the list of references
%using apacite.sty. Commands using natbib.sty MUST be deactivated first!
%\renewcommand\bibliographytypesize{\fontsize{10}{12}\selectfont}% To set the
%list of references in 10 point font using apacite.sty. Commands using
%natbib.sty
%\MUST be deactivated first!
%\theoremstyle{plain}% Theorem-like structures provided by amsthm.sty
\newtheorem{theorem}{Theorem}[section]
\newtheorem{lemma}[theorem]{Lemma}
\newtheorem{corollary}[theorem]{Corollary}
\newtheorem{proposition}[theorem]{Proposition}
%\theoremstyle{definition}
\newtheorem{definition}[theorem]{Definition}
\newtheorem{example}[theorem]{Example}
%\theoremstyle{remark}
\newtheorem{remark}{Remark}
\newtheorem{notation}{Notation}
\usepackage{amsmath}
\usepackage{hyperref}
\usepackage{makecell}
\usepackage{graphicx}
\usepackage{longtable}
\usepackage{supertabular}
\usepackage{morefloats}
\usepackage{tablefootnote}
\usepackage[final]{pdfpages}
\usepackage{import}
\usepackage{filecontents}
\usepackage{multirow}
\usepackage{booktabs}
\usepackage{siunitx}
\usepackage{soul}
\usepackage{textcomp}
\usepackage{threeparttable}
\setlength\bibhang{12pt}
\renewcommand\bibliographytypesize{\fontsize{10}{12}\selectfont}
%\usepackage{cite}
\renewcommand{\bibname}{References}
\begin{document}
TEST
\bibliographystyle{apacite}
\bibliography{thesis}
\end{document}