Thanks for the suggestions. I have managed to get NSC back through Safari, but still getting same original message if I go direct to Google or Chrome (I would mention that I am as adept with this technology as Bens Grandad was).
I don't use Archive.org, and neither can I find a preferences...
I've been getting the message 'The operation couldn't be completed. (kCFErrorDomainCFNetwork error 303.)' for several days on my iPad and can't access NSC from there. My PC and phone are working fine though.
I tried clearing cookies and history as suggested but to no avail. Any further...