I used a backup Clone I made before these problems started to restore my working Os to the current C: drive.
Theoretically the problem should be solved right? Wrong, there still was the problem that the Store App wouldn’t connect to my Microsoft account “Something went wrong try again later”.
It’s strange that a failure in two apps (Microsoft-Store and Xbox Live) can’t be corrected in a simple way. The only solution was to take drastic measures.
I reinstalled Windows (keeping Apps and Personal files). When the installation was finished and after rebooting several times due to continual updates I could start to use my Pc again. It took me a while to tweak it to my liking again but I managed to get all my programs working again.
When I started Msfs it would nicely login to the Store- and Xbox app and launch Msfs normally. I still think it’s strange to have to take drastic measures just to reset a few files.
Anyway, I’m up in the air again.
This topic can be closed.