Thanks for your suggestions.
Disabling apparmor made no
difference.
"sestatus" returns "command not
found" and the only other search engine references I can find
about selinux is how to install it on 16.04. And other
references that it been dead since Karmic.
The command sting I am running is
from an old (cannot find it on Backuppc documentation anymore)
wiki page I printed years ago. I not sure what you mean when
you asked "What is the current working directory when you ran
the above test?" It was run as sudo by an administrative user
on the Backuppc machine.
And, last question, I am not sure
what you mean by "by using a locale other than C" . . . like
'C' the language? How would I " . . . change the OS default
locale to C, and then try it again"? (OS is Ubuntu 16.04)