[Capricorn]

Hey,

I have a weird problem in the Calibre editor of Calibre v4.9.

I have been editing some books with Calibre 4.8 and the calibre editor yesterday and today. That worked fine.
I then upgraded to Calibre v4.9 and continued editing.
Now, when I run the editor and use "check book" I get this message:

Failed to process name_of_html file

However, when I look at this html file, I can not find any errors.

When I then re-run check, it sometimes gives this message for the same file and sometimes for other html files.
When I use epubcheck plugin, the book is fine and there are no errors. I can read the book, go to the html file that gives the error and it all works.

I then checked a book I did yesterday with Calibre v4.8. This book had no errors yesterday, not in check book, not in epubcheck. But with Calibre v4.9, when I run the check, it gives me the above error message.

I have now tried this on 5 different books and each book throws up this error, when running "check book" in the Calibre editor for v4.9. And here too the html files that get marked, change all the time when re-running "check book".

And when I use the sigil editor to look at these books, everything works fine.

I run Calibre on windows 10 v1909 with the latest updates applied.

What am I doing wrong? Or is this some bug?

Some help would be much appreciated.