I'm trying to write this 3x12 matrix, but when compiling I get the following: "Additional alignment tab has been changed to \cr" I don't know what's going on, I'll leave here what I have in the preamble to see what could be causing the conflict
\documentclass[12pt,a4paper]{article}
\usepackage[latin1]{inputenc}
\usepackage[spanish]{babel}
\parindent=0mm
\usepackage{makeidx}
\usepackage{amsmath,amssymb,amsthm,amsfonts,latexsym,cancel,tikz,colortbl}
\usepackage{array}
\usepackage{ragged2e,bm}
\usepackage{txfonts}
\usepackage{esvect}
\usepackage{xcolor}
\usepackage{braket}
\usepackage{enumerate}
\usepackage[shortlabels]{enumitem}
\usepackage{titlesec}
\usepackage{booktabs}
\usepackage{float}
\setcounter{tocdepth}{1}
\author{}
\title{CÓDIGOS ALGEBRAICO-GEOMÉTRICOS Y ALGUNAS APLICACIONES}
\newcolumntype{P}[1]{>{\RaggedRight\hangafter=1\hangindent=3.3em}p{#1}}
The code I am using to write the matrix is
\begin{equation*}
\begin{pmatrix}
0&0&1&1&2&2&3&4&4&5&6&0\\
1&6&3&4&3&4&0&3&4&0&0&1\\
1&1&1&1&1&1&1&1&1&1&1&0
\end{pmatrix}
\end{equation*}
amsmathpackage defines a counter namedMaxMatrixColsand sets its default value to 10. It's relevant for thematrix,pmatrix,bmatrix, andvmatrixenvironments. To increase the value to, say, 12, write\setcounter{MaxMatrixCols}{12}. – Mico Sep 15 '22 at 02:04txfontspackage; instead, do load thenewtxtextandnewtxmathpackages. No need to load theamsfontspackage explicitly, as it's loaded automatically by theamssymbpackage. Since you loadamssymb, there can be no good reason for loading thelatexsympackage. Don't load bothenumerateandenumitem; hint: load just the latter package. And, unless your computing setup is ancient (say, more than 10 years old...), do get rid of\usepackage[latin1]{inputenc}. – Mico Sep 15 '22 at 02:09