I have installed Texlive on a new Windows and recognised, that I now receive an error from the nicematrix package.
This is the result with the version from Overleaf (using LuaLaTeX)
This is the result when using 6.26d of nicematrix.sty
This is the MWE:
\documentclass{article}
\usepackage{fontspec}
\usepackage{mathtools} % includes: \usepackage{amsmath} (-> needed e.g. for bmatrix) !! load BEFORE \usepackage{unicode-math}
%\mathtoolsset{mathic=true} % https://tex.stackexchange.com/questions/3490/bad-spacing-of-math-letters-within-italic-text
\usepackage{unicode-math} %Unicode mathematics support for X?TEX and LuaTEX
\usepackage{nicematrix}
\title{Your Paper}
\author{You}
\begin{document}
\maketitle
\begin{abstract}
Your abstract.
\end{abstract}
\section{Introduction}
\begin{equation}
\mathbfit{W}{x\star} =
\begin{NiceArray}{[cccc]@{\quad\enspace}l}
w{x\star,{0,1}} & w_{x\star,{0,2}} & \ldots & w_{x\star,{0,h}} & \text{bias} \
w_{x\star,{1,1}} & w_{x\star,{1,2}} & \ldots & w_{x\star,{1,h}} & \Block{4-1}{d \text{ features}} \
w_{x\star,{2,1}} & w_{x\star,{2,2}} & \ldots & w_{x\star,{2,h}}\
\vdots & \vdots & \ddots & \vdots \
w_{x\star,{d,1}} & w_{x\star,{d,2}} & \ldots & w_{x\star,{d,h}}\
\CodeAfter
\UnderBrace[shorten,yshift=0pt]{last-1}{last-4}{h,,\mathrm{hidden: units}}
\SubMatrix{.}{1-4}{1-4}{}}[xshift=2mm]
\SubMatrix{.}{2-4}{5-4}{}}[xshift=2mm]
\end{NiceArray}
\end{equation}
\end{document}
If I remove [ and ] in \begin{NiceArray}{[cccc]@{\quad\enspace}l}, the error is gone, but also the brackets of the matrix.
nicematrix). As a workaround, you can write\left[and\right]instead of[and]. – F. Pantigny Feb 18 '24 at 19:52