Ah, I forgot to attach the file. Here it is.

(file #521)

I have a minimal file at the end of this message. If I run

make4ht -a debug -m draft test.tex

then I get this message.

(/usr/local/texlive/2022/texmf-dist/tex/generic/tex4ht/html5.4ht)) (./test.aux)
! TeX capacity exceeded, sorry [input stack size=10000].
\old:outputpage ->\old:outputpage
{}
l.9 \end{document}

No pages of output.
Transcript written on test.log.
[FATAL] make4ht-lib: Fatal error. Command htlatex returned exit code 1

If I comment out the \usepackage{animate} line then it works great, and I can view the .html file perfectly.

Regards,
Jim Hefferon

=================================

\documentclass{book}
\usepackage{graphicx}
\usepackage{animate}

\usepackage{lipsum}
\begin{document}

\lipsum[1-3]
\end{document}