> TeX4ht files in Miktex are probably too old. I've sent a mail with an update > to the Miktex maintainer, so it should be fixed soon hopefully.
While looking at this at tex.sx I saw in texlive a (\end occurred inside a group at level 1) message in the log with make4ht (both with -l and without) with this document: \documentclass{article} \begin{document} Hello world \end{document} -- Mit freundlichen Grüßen Ulrike Fischer