This should be fixed in the sources.

Compiling the following source with
`htlatex x.tex xhtml,mathml`

gives error
`! TeX capacity exceeded, sorry [parameter stack size=20000].`

```latex
%% File x.tex
\documentclass{article}
\usepackage[spanish]{babel}
\begin{document}
\selectlanguage{spanish}
La desinformación
\end{document}

The problem seems related to some interaction between "mathml" and "spanish".

It happens compiling with
htlatex x.tex xhtml,mathml
htlatex x.tex html,mathml

It does not happen compiling with
htlatex x.tex xhtml
htlatex x.tex html

and it does not happen for many other languages.
E.g. it does not happen if the tex source contains:
\usepackage[LANGUAGE]{babel}
...
\selectlanguage{LANGUAGE}
for LANGUAGE in british, french, brazil, portugese, italian, german