stuck with install XWD premium 15 ? Need some help to understand what's going on

I am running XWD premium 12 on my desktop/W7. I asked support for a 2nd installation on my surface/W10 and they granted me a key. My usual e-mail address was refused but ok, I could install it using a my e-mail address, proabably I didn't remember. Installation folder was - as usual - /Xara. So far so good, I am now running XWD15 on my surface.

Now I went back to my desktop (W7) where XWD 12 is still running since 2017, so they told me I could download from the same link XWD15 exe and I should best install it alongside. ok.

When I did I first noticed the installation folder was /Magix, not /Xara. Annoying, but ok. Then when launching XWD I got a pop-up from Magix saying that I first have to de-activate it on my current device and please fill in your pw.

What ? Activate/de-activate ? Xara versioning has never been more confusing. I was even not aware that XWD12 users who payed for support could upgrade to XWD15 because the software systematically tells you that you have the latest version when you check for updates ! Link below.

"Version 15 is actually a standalone program which you can install directly from the link below:
http://dl03.magix.net/webdesigner15premium_dlm.exe"