Thanks for the reply.
This issue is of very recent onset (last week or so) on a computer on which File Explorer has successfully accessed both MyBookLive and WDMyCloud for well over a year without any issues.
I am starting to wonder if it may have something to do with one of Microsoft’s ubiquitous surprise updates. I remember that a day or so before I noticed the issue, the computer had restarted itself and was awaiting entry of the password. I hadn’t noticed that an update was pending, but I probably missed it.
