This is a bug which creates a security issue though I concede that it is now water under the bridge. I have resolved the issue to my satisfaction and want to thank you guys for the advice and information offered to me. The contrived non-availability of the file 'opera_autoupdate.exe' did the trick.
I have a notion that using Opera 12.17 confers a degree of security through obscurity. I am not complacent and employ anti-exploit tools, amongst many other things, to assure myself a fairly peaceful life. The facility of TLS 1 through 1.1 and 1.2 allows me to swan around wherever I like. The Qualys SSL Labs Client Test (via https://www.ssllabs.com/projects/index.html) is passed with flying colours Those web sites that don't work with Presto are ignored.