I've sourced and downloaded a copy of 1.17, and removed the rubbish that flew in this morning. All the new downloads in the Kindle Library removed and reinstalled under 1.17.
Calibre downloads and, more importantly, converts to ePub.
That was rather vicious of Amazon to bypass its own check on "do not install new versions". Something to watch out for in the future.
Not too sure why I couldn't get the latest plugin to function correctly under 1.26 - nothing on Apprentice Alf gave me a clue.
for Calibre and Apprentice Alf.....