Overfull \hbox and Package array Errors. Latex tabular - latex

Question

I am getting trouble to fit my table - tabular to the paragraph width.
This is the error:
Overfull \hbox (341.06795pt too wide) in paragraph at lines 391--411
Package array Error: Illegal pream-token (M): `c' used.
Package array Error: Illegal pream-token (4cm): `c' used
I have been trying one thousand things and nothing seems to work.
I am using this template from Overleaf, where you can find the document class.
This is my code.
\documentclass{JASSS}
\usepackage{amsmath,systeme}
\usepackage{tabularx,colortbl}
\usepackage{booktabs}
\title{XXXXX}
\reviewcopy{true}
\author[1]{}
\affil[1]{}
\email{XX}
\usepackage{natbib}
\setcitestyle{authoryear,round,aysep={}}
\begin{document}
\maketitle
\begin{abstract}
Bla bla
\end{abstract}
\section{xxxx}
\begin{table}[h!]
\centering
\begin{tabular}{ |M{4cm}||M{4cm}|M{4cm}|M{4cm}|}
% \begin{tabular}{|c|c|c|c|}
\cline{2-4}
\multicolumn{1}{c|}{} & \multicolumn{3}{c|}{Initial value parameter combinations ($t_0=1932$)} \\
\hline
Scenarios from 2020 & $\phi_{B}=\phi_{C}=0.05$ and 1932 electoral results & $\phi_{B}=0.05, \phi_{C}=0.055$ and 1932 electoral results & $\phi_{B}=\phi_{C}=0.05$ and electoral tie \\
\hline
$\phi_{D}=\phi_{E}=0.01$, $\gamma_{B}=\gamma_{C}=\gamma_{D}=\gamma_{E}=0.01$ & S0000 & S0100 & S1000 \\
\hline
\rowcolor{blue!20}
$\phi_{D}=0.015,\phi_{E}=0.01$, $\gamma_{B}=\gamma_{C}=\gamma_{D}=\gamma_{E}=0.01$ & S0001 & S0101 & S1001 \\
\hline
\rowcolor{red!20}
$\phi_{D}=0.01,\phi_{E}=0.015$, $\gamma_{B}=\gamma_{C}=\gamma_{D}=\gamma_{E}=0.01$ & S0010 & S0110 & S1010 \\
\hline
\rowcolor{yellow!20}
$\phi_{D}=0.01,\phi_{E}=0.01$, $\gamma_{B}=\gamma_{C}=\gamma_{D}=\gamma_{E}=0.015$ & S0011 & S0111 & S1011 \\
\hline
\end{tabular}
\bibliographystyle{jasss}
\bibliography{references}
\end{document}

Answer 1

The M column type is not defined by default. If you want to use it, you have to somehow define it. I don't know what you indent it to do, but here some dummy code:
\documentclass{JASSS}
\usepackage{array}
\usepackage{amsmath,systeme}
\usepackage{tabularx,colortbl}
\usepackage{booktabs}
\newcolumntype{M}[1]{p{#1}}
\begin{document}
\begin{table}[h!]
\centering
\begin{tabular}{ |M{4cm}||M{4cm}|M{4cm}|M{4cm}|}
% \begin{tabular}{|c|c|c|c|}
\cline{2-4}
\multicolumn{1}{c|}{} & \multicolumn{3}{c|}{Initial value parameter combinations ($t_0=1932$)} \\
\hline
Scenarios from 2020 & $\phi_{B}=\phi_{C}=0.05$ and 1932 electoral results & $\phi_{B}=0.05, \phi_{C}=0.055$ and 1932 electoral results & $\phi_{B}=\phi_{C}=0.05$ and electoral tie \\
\hline
$\phi_{D}=\phi_{E}=0.01$, $\gamma_{B}=\gamma_{C}=\gamma_{D}=\gamma_{E}=0.01$ & S0000 & S0100 & S1000 \\
\hline
\rowcolor{blue!20}
$\phi_{D}=0.015,\phi_{E}=0.01$, $\gamma_{B}=\gamma_{C}=\gamma_{D}=\gamma_{E}=0.01$ & S0001 & S0101 & S1001 \\
\hline
\rowcolor{red!20}
$\phi_{D}=0.01,\phi_{E}=0.015$, $\gamma_{B}=\gamma_{C}=\gamma_{D}=\gamma_{E}=0.01$ & S0010 & S0110 & S1010 \\
\hline
\rowcolor{yellow!20}
$\phi_{D}=0.01,\phi_{E}=0.01$, $\gamma_{B}=\gamma_{C}=\gamma_{D}=\gamma_{E}=0.015$ & S0011 & S0111 & S1011 \\
\hline
\end{tabular}
\end{table}
\end{document}