[BaconButty]

Thanks for the replies.

When I checked here last night after the Calibre update removed the plug-in icon, I read that an update would be made public in a few hours.
When I checked the plug-ins earlier and saw the update listed, I tried to apply it, got the message I posted, then a pop-up saying the plug-in would be un-installed.
I assumed the un-install had been done and did not realise this had to be done manually.

I have now un-installed, restarted, re-installed and created a cover.

It works fine, but I cannot use the font I had used for all my covers up to now, as it is no longer listed...


Thanks again.