Problem recognised (but not solved). The issue is with Firefox 40.0.3 not able, or willing, to show the results. IE-9 & IE-11, and Chrome 44.0.2403.157, display results perfectly. All browsers are running on Win7 Pro.
Firefox does not display the StatCounter log-on screen, so there’s no chance to go further. The only thing at the bottom of the (blank) screen is the WordPress footer and version number.
Take it from there, Batman.