Thank you so much for this post. I had been having nothing but trouble with Calibre and Kindle e books for a month or so. I didn't realise I had a new version of PC for kindle which was stopping me from converting any books on calibre. I had even resorted to downloading a azw converter. I didnt buy it though and then today I download a new book and get ready to convert it an it tells me its a KFX format. Luckily I was diverted to this site.My new books downloaded as AZW but converted easy enough to Mobi.I have gone back to 1.17.0 an it works fine.
