It took me quite some time to figure out why some TV series where not scraped: It turned out thetvdb.com scraper doesn't scrape .NFO files if they are not in UTF format. This is nowhere mentioned on the Kodi Wiki. It probably only happens if the .NFO file contains non-English content, but since Kodi has an international user base this information is important to mention. The above may also be true for other media like music albums. I noticed the few NFO files I created in the past for music albums by Polish artists are also in UTF format.
Therefore I would like to suggest to add an extra bullet point under "1.2 Create an .NFO file (recommended)":
- Make sure the .NFO file is UTF-8 formatted. Please note Windows creates new text documents in ANSI format by default.