I checked all solutions for similar questions to no avail. I have an extra empty page in my TOC, and I noticed that if I move \frontmatter and put it after the title page, it is solved! but another empty page is introduced after title page this time!! Here's my code for reproducibility
\documentclass[12pt,openany,a4paper]{book}
\pagestyle{headings} % Chapter on left page, Section on right.
\usepackage{titlesec}
\titleformat{\chapter}[hang]{\Huge\bfseries}{\thechapter\hspace{20pt}}{0pt}{\Huge\bfseries}
\titlespacing{\chapter}{0pt}{-40pt}{1em}
\raggedbottom
\usepackage[margin=2.5cm]{geometry}
\usepackage{blindtext}
\usepackage{multirow,tabularx}
\usepackage[%
bibstyle=ieee,
citestyle=numeric-comp,
isbn=false,
doi=false,
sorting=none,
url=false,
defernumbers=true,
bibencoding=utf8,
urldate=long,
backend=biber
]{biblatex}
\bibliography{ref}
\begin{document}
\frontmatter
% By default, frontmatter has Roman page-numbering (i,ii,...).
\begin{titlepage}
My title
\end{titlepage}
\chapter{Abstract}
\blindtext
\tableofcontents
\mainmatter
\chapter{Introduction}
\blindtext
\chapter{Methodology}
Provides an outline of the methodological approach including a theoretical justification of the approach.
Describes any analytical techniques and research designs, if appropriate.
\chapter{Outcomes}
Describes the results to date and expected outcomes of future studies.
Discusses the findings.
While the outcome presented above is reasonable, it is still behind the ultimate target, which is a working algorithm on real human heads. Therefore, we keep pushing in this direction.
In more challenging and realistic scenarios
We report that fragility of neural nets is seriously limiting its use in such a sensitive application.
\chapter{Time-line}
This must include a clear plan for the completion of experiments, write up of papers (including a targeted list of suitable journals and conferences) and write up of the thesis.
\section{Year 1 (2019)}
\begin{tabularx}{\textwidth}{l}
\hline \vspace{-0.3cm}
\end{tabularx}
\noindent
\begin{tabularx}{\textwidth}{@{} p{2cm} p{13.5cm}}
\\ Q1 -- Q2 &
\vspace{-0.74cm}
\begin{itemize}
\item Getting acquainted with the project, the technical details entailed with calibrating the system and the type of data provided.
\item Reviewing the literature on machine learning.
\end{itemize}
\\ Q3 -- Q4 &
\vspace{-0.74cm}
\begin{itemize}
\item blah
\item blah
\end{itemize}
\end{tabularx}
\section{Year 2 (2020)}
\begin{tabularx}{\textwidth}{l}
\hline \vspace{-0.3cm}
\end{tabularx}
\noindent
\begin{tabularx}{\textwidth}{@{} p{2cm} p{13.5cm}}
\\ Q1 -- Q2 &
\vspace{-0.74cm}
\begin{itemize}
\item \blindtext
\item \blindtext
\end{itemize}
\\ Q3 -- Q4 &
\vspace{-0.74cm}
\begin{itemize}
\item \blindtext
\item \blindtext
\end{itemize}
\end{tabularx}
\section{Year 3 (2021)}
\begin{tabularx}{\textwidth}{l}
\hline \vspace{-0.3cm}
\end{tabularx}
\noindent
\begin{tabularx}{\textwidth}{@{} p{2cm} p{13.5cm}}
\\ Q1 -- Q2 &
\vspace{-0.74cm}
\begin{itemize}
\item \blindtext
\item \blindtext
\end{itemize}
\\ Q3 -- Q4 &
\vspace{-0.74cm}
\begin{itemize}
\item \blindtext
\item \blindtext
\end{itemize}
\end{tabularx}
\chapter{Bibliography}
\begin{appendix}
\chapter{Publications}
\section{Unpublished work}
Hi there
\end{appendix}
\end{document}
tabularxwithout anXcolumn.\begin{tabularx}{\textwidth}{@{} p{2cm} p{13.5cm}}should be\begin{tabular}{@{} p{2cm} p{13.5cm}}– David Carlisle Dec 30 '19 at 20:54\mainmatter. Does https://tex.stackexchange.com/questions/498201/preventing-mainmatter-from-inserting-a-blank-page help? – David Purton Dec 31 '19 at 00:42