tex4ebook displays accents as wrong characters [duplicate]

Question

I'm trying to make an ebook, on windows 7 sp1, with both italian and cyrillic (and chinese in future).

Minimum example with LuaTeX, Version 1.12.0 (MiKTeX 20.11):

\documentclass[12pt,a4paper,openright,oneside]{book}
\usepackage{fontspec}
\setmainfont{Dejavu Serif}
\setmonofont{Courier New}
%
\begin{document}
aeeiou

\'a\'e\'i\'o\'u

àèéìòù

пожалуйста
\end{document}

Compiling with lualatex.exe works fine:

but it does not with:

C:\PATH>tex4ebook.exe -l .\file.tex "html5,charset=utf-8" " -cunihtf -utf8"

that gives:

The problem is already there in the html file.

I have also tried the command without the options, i.e. C:\PATH>tex4ebook.exe -l .\file.tex.

The same apply with pdfTeX, Version 3.14159265-2.6-1.40.21 (MiKTeX 20.11), C:\PATH>tex4ebook.exe .\file.tex and:

...
\usepackage[T2A,T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[russian,italian]{babel}
...
\foreignlanguage{russian}{пожалуйста}

This example misses the cyrillic hen compiled with lualatex, but does not solve the accents problem either:

Thanks a lot.

Answer 1

I solved updating in MikTex console like in the following:

Nothing very old, but something needed a repair. I don't know what the exact problem was.