Kindle not recognised by Calibre suddenly after updating to Calibre 8.67
I have an old Kindle not the touch ie it has a keyboard.
It was working perfectly with Calibre until I Calibre to updated today 0 .8.67
It has stopped recognising my kindle at all.
I am working with OSX on a macbook pro.
I have tried rebooting the machine - unplugging the kindle and re plugging it into the computer. Nothing is working. It still says cannot find any kindle
It is showing in my devices as mounted.
Please can you tell me what to do - is there a way of going back to the previous working installation ?