So I’ve restored the folder, taken what I need out of it into a new folder, rescanned and the old folder is safely in the chest - if I decide there’s something else I need in it, I can do it again.
One strange thing that has happened, each time I select “non-removable disks only” but the scan happily moves on to external drives. Is this a bug?
Thanks for your feedback…!
Good you could save your important mails… 
asyn