When i saw this post i tried it out on my laptop.
I get the same fault and message.
It's strange. The correct plug-ins are actually installed, but the changedate for the plug-in in the install folder does'nt change to the install date. The install date for the plug-in it self is correct. And all seems to be correct in Windows controlpanel. There seems to be something wrong with the installer.
Look like Arturia should stop this update untill this install issue is fixed.
I can't see the update on the download website page yet.