SUCCESS !!!
In Settings.php, I changed …
// default settings needed for various pages when the weather software plugin is not installed.
// do not change these
$SITE['WXsoftwareURL'] = '#';
$SITE['WXsoftwareLongName'] = '(unspecified)';
$SITE['WXtags'] = ' ';
to …
// default settings needed for various pages when the weather software plugin is not installed.
// do not change these
$SITE['WXsoftwareURL'] = '#';
$SITE['WXsoftwareLongName'] = '(unspecified)';
$SITE['WXtags'] = 'testtags.php';
… and it works.
Not sure if this is the correct way of fixing the problem, or if it affects anything else, but it’s looking good.
HAPPY.