Had been patient (since early November download with weekly program updates coming in just fine) trying repeatedly the various suggestions (turn-off anti-virus, disable firewalls, reset router, re-do screen resolution and/or scaling, flushdns etc command prompts). I have up-to-date Windows 10 Pro 1909 build. Also tried Copy/Paste on the quickly appearing then disappearing blank activation dialogue; no luck. Fiddled with various browser privacy and security settings just in case; no luck. Was almost ready to either call TT (I did not want that much pain though) or go to manual preparation (I've used TT Deluxe for years).
Setting up TT Deluxe 2020 compatibility (to Windows 8 ) then running as adminstrator did the trick - the activation dialogue initialized, offered the activation code slots, and then accepted the code, started TT. Huzzah!
But why, oh why do ordinary users have to jigger this warped system?
