@Robert-Basque It should help if you disable the controlled folder access temporarily and try to install the software again. You can enable it again if everything is installed and running.
The 101 error has been known for quite a while. I raised a ticket about it recently and the reply was that Magix would probably do nothing about it. As far as I can tell, it has no impact on the program, other than being annoying. Strangely, after a few weeks of using the program, the error has disappeared. Go figure.