@Riverheadstudios, @Egregius – UPDATE
Yesterday, I also had installed the latest Wacom driver 6.3.43-3 and even chosen Viveza 3 application. With some deeper research today I came across videos about Wacom tablet & Windows.
This one https://www.youtube.com/watch?v=YeCMw0na2NY is in German.
Activate the subtitles and maybe lower the speed 
- after more general, still interesting explanations check at 2:45 for the white circles
caused by Windows (!) → the presenter’s reddish marking - at 3:46 he goes to the control panel …
( as you can’t uninstall the Windows driver deactivate the disturbing settings ) - at 3:58 the white circles
To complement the information check for this video https://www.youtube.com/watch?v=rTAc7aFT2AI
(in English). After some ‘forewording’ you may go to 16:25 …
and from the third comment (Thomas Hedman)
- Q: Hi David, I use PC Windows 10, do you have a tip on how I can avoid the ring coming up?
- A: Aye I can help. If you go to your Control Panel and select Pen and Touch, then select the
option in the middle window that says Press and Hold. Now click Settings below that window.
At the top of the new window make sure the box is UNCHECKED that says “Enable press and hold for right-clicking.” That will stop the tablet from trying to make the circle/selection
Might need a reboot too, just to make sure it holds. Anytime you do a major update to Windows,
you may have to return to this menu and do this again, as Microsoft just LOVES to reset user
settings to default. Thanks for watching!
So, that should do the trick to avoid the white circles.
On my machine, I don’t see this in the control system, but then the tablet mode is not activated
and I even unchecked some settings for ‘Windows Ink’.
Now in the Wacom driver, I changed everything that might refer to windows tablet (Konstanter Druck)
or Windows Ink.
So today, after some maneuvering I COULD USE THE Wacom TABLET
with Silver Efex Pro 3 and Viveza 3 – exporting from PL4.3 (they don’t work in old PS).
But the handling of PL4 is simply better than the ‘new’ Nik programs – to say it nicely,
see About Nik 4 - SilverEfex 3 & Viveza 3
have fun, Wolfgang