Hello dagon,
The problem occurs when downloading the article at
https://www.bbc.co.uk/news/world-51235105. It contains a HUGE table listing "coronavirus data". calibre by default will attempt to split HTML files larger than 260KB. But it cannot split tables, so when this happens it raises an exception and exits before it can finish making the eBook. Here's a quick fix that simply avoids the downloading of this particular article. It should then finish making your eBook.