\hbar not working

[DuckTigger]

Hi, \hbar doesn't seem to work with amssymb at the same time.
MWE:

\documentclass[12pt,phd,a4paper,oneside]{ucl_thesis}

\usepackage{amssymb}
\begin{document}
    \begin{equation}
        \hbar
    \end{equation}
      $ \hbar $
\end{document}

This fails with the Undefined control sequence error.

Tex version:

latex --version
pdfTeX 3.141592653-2.6-1.40.24 (TeX Live 2022)
kpathsea version 6.3.4
Copyright 2022 Han The Thanh (pdfTeX) et al.
There is NO warranty.  Redistribution of this software is
covered by the terms of both the pdfTeX copyright and
the Lesser GNU General Public License.
For more information about these matters, see the file
named COPYING and the pdfTeX source.
Primary author of pdfTeX: Han The Thanh (pdfTeX) et al.
Compiled with libpng 1.6.37; using libpng 1.6.37
Compiled with zlib 1.2.11; using zlib 1.2.11
Compiled with xpdf version 4.03

[DuckTigger]

Fixed by the comment on a similar issue: kks32/phd-thesis-template#223 (comment)