Ha ha ha. ****. Now how did that happen!? And how come I didn't even notice.
I'm collaborating with a bunch of engineer scientists who are all running PC. My MacBook Pro is set up to also run PC files (NTFS for Mac). An app I can't remember updating recently.
I'm going to check that NTFS for Mac is up to date. I've already got a transfer going to copy the whole drive onto a RAID system (properly formatted). Aie yie yie!! I hate USB-3. This is an ?? 17 hour transfer. Shutting it down.
I'm going to check out NTFS for Mac. Because I remember working with this material back in 22. But I'm going to move it to a properly formatted drive in the night tonight regardless.
Will report back once I've checked out my NTFS for Mac ... which may, updated, be a temporary solution.
Thank you most kindly Luis and Tom ... I'll click Best Answer once we figure out which it might be. More soon...
And will report back.