The folder WindowsApps is a protected folder. You won’t be able to drill down into it, but you can verify it exists (its a hidden folder, so show hidden files).
If it does exist, I’d guess that the system doesn’t have the access to the files folders under that, for whatever reason, as an unintended side effect of the repair.
I’d start by seeing if any new windows store apps can be installed to that same c:\program files\windowsApps folder. If not, then it is a windows and file permissions issue.
If you can install windows store apps, then you know the system can at least access that folder and do what it needs. Next, I’d try to update other windows store apps. If they all update fine, then the windowsapps folder and permissions are probably fine. If not, its a windows issue to look further.
But if other apps can update/install/etc. and only msfs is having issues, I’d remove it and re-install.