Installation not successful, says it’s already installed, and that I should de-install the current version first.
While in fact there is no such previous installation (there has been a recent Confidential giveaway but with a 1-year license only so I didn’t install that one) but there is an installation of Tabbles which is from the recent giveaway over here. So possibly Confidential installation will work if I de-install Tabbles first, but Tabbles being more important to me, that wouldn’t be a solution for me.
I’m quite surprised a previous Tabbles installation has this effect upon a Confidential installation, from the same developer.