Hello everyone!
I have been using the free version for quite some time now, and I am very happy with it.
So, wanting to support the developers (and get the extra models), I decided to purchase the App Store version.
That went well apart up to the point where Launchpad says "Installing / 245.6 MB of 245.6 MB" for hours, and apparently nothing happens any more.

Moving the "Sweet Home 3D" folder out of Library/Preferences/ and restarting the Mac did not help.
I am running macOS 10.15.7 Catalina and I am trying to install version 6.4.7.

Did anyone encounter the same issue, or do you have any idea what might help?
Any advice is greatly appreciated!