When I fire up the sim I see the normal window, but then there's a pop up right above it that reads;  " You'll need a new app to open this MsGamingoverlay. " Below this message there's a box to click and next to it reads; " Always use this app. " The Generating Scenery Box reads; 42% and is frozen there.

I was able to eliminate the App pop up, but now it's stuck on 43%.

If  you added  any  scenery  etc  it  will always  take  longer   the  first  time  it  loads

You were right, it took about twenty minutes then it opened. Thank you