! Argument of \use_none:n has an extra }

[kkgped]

The following MWE

\documentclass{article}
\usepackage{chemformula}
\begin{document}
    \ch{2 CO2 -> 2 CO + O2}
\end{document}

leads to the following error:

Prozess gestartet: lualatex.exe --shell-escape --synctex=-1 --output-format=pdf --output-directory="Z:\test.texout" "Z:\test\test.tex"

This is LuaHBTeX, Version 1.22.0 (MiKTeX 25.4 Portable) system commands enabled. (Z:/test/test.tex

LaTeX2e <2025-06-01> patch level 1 L3 programming layer <2025-07-11>

(C:/PortableApps/Miktex/texmfs/install/tex/latex/base/article.cls

Document Class: article 2025/01/22 v1.4n Standard LaTeX document class

(C:/PortableApps/Miktex/texmfs/install/tex/latex/base/size10.clo ) )

........ > ....... ........ ........

! Argument of \use_none:n has an extra }. \par

But the following code compiles:

\documentclass{article}
\usepackage{chemformula}
\begin{document}
    \ch{2~CO2~->~2~CO~+~O2}
\end{document}