My question is similar to this question But it seems different. I wrote this code:
\documentclass[letterpaper,11pt]{article}
\usepackage{tabularx}
\section{Selected courses}
\begin{center}
\begin{tabular}{ m{8cm} m{6.5cm} r{2cm} }
C & C & C \\
C & C & C \\
\end{tabular}
\end{center}
My code was working last month without error. but I opened it today and got this error:
Package array Error: Illegal pream-token (2cm): `c' used.
See the array package documentation for explanation.
Type H <return> for immediate help.
...
l.295 ...\begin{tabular}{ m{8cm} m{6.5cm} r{2cm} }
Try typing <return> to proceed.
If that doesn't work, type X <return> to quit.
I think it's maybe related to the package update.
r{...}
withwr{...}
\begin{document}...\end{document}
. That way the code you show avoids spurious errors and actually reproduces (only) your problem. (I can't offer the incentive that I will upvote your question if you do that, because I already voted.)