[Leonatus]

Originally Posted by Doitsu

You definitely should make a backup copy of your e-book before running the plugin.

I made several ones.

But, after all, it's the same error message.

Edit: Just for testing purposes, I downloaded the "HTML2Epub"-Plugin, and the error message is quite the same:

Status: failed

Python version:  3.8.3 (tags/v3.8.3:6f8c832, May 13 2020, 22:20:19) [MSC v.1925 32 bit (Intel)] 

Running HTML2Epub...Please wait...this might take several minutes.

 -- Input file encoding is: CP1252
 -- Convert input file to utf-8 if required


 -- Processing automatic tasks...
 -- Clean and reformat the html
 -- Input file encoding is: UTF-8
 -- Convert input file to utf-8 if required

 >>> Doctype is: LibreOffice

 -- In cleanHTML processing file...C:\Users\Juerg\AppData\Local\Temp\tmpt0fla1av\Léon de Tinseau, L'attelage de la Marquise.html
 -- Remove blank lines
 -- Remove empty tags
 -- Remove tabs and spaces
Traceback (most recent call last):
  File "C:\Program Files\Sigil\plugin_launchers\python\launcher.py", line 142, in launch
    self.exitcode = target_script.run(container)
  File "C:\Users\Juerg\AppData\Local\sigil-ebook\sigil\plugins\HTML2Epub\plugin.py", line 143, in run
    cleanHTML(WDIR, os.path.join(WDIR, html_file))
  File "C:\Users\Juerg\AppData\Local\sigil-ebook\sigil\plugins\HTML2Epub\cleaner.py", line 43, in cleanHTML
    docTidyNoWrap(wdir, file)
  File "C:\Users\Juerg\AppData\Local\sigil-ebook\sigil\plugins\HTML2Epub\doc_tidy.py", line 129, in docTidyNoWrap
    html, errors = tidy_document(xhtml, options=base_options)
  File "C:\Users\Juerg\AppData\Local\sigil-ebook\sigil\plugins\HTML2Epub\tidylib\tidy.py", line 292, in tidy_document
    return get_module_tidy().tidy_document(text, options)
  File "C:\Users\Juerg\AppData\Local\sigil-ebook\sigil\plugins\HTML2Epub\tidylib\tidy.py", line 304, in get_module_tidy
    _tidy = Tidy()
  File "C:\Users\Juerg\AppData\Local\sigil-ebook\sigil\plugins\HTML2Epub\tidylib\tidy.py", line 158, in __init__
    raise OSError(
OSError: 
Could not load library: C:\Users\Juerg\AppData\Local\sigil-ebook\sigil\plugins\HTML2Epub\tidylib\win32\tidy.dll
Error: 
Could not load library: C:\Users\Juerg\AppData\Local\sigil-ebook\sigil\plugins\HTML2Epub\tidylib\win32\tidy.dll