I was in the SU4 beta. I opted out of the beta, updated 1.66GB in the MS store, and launched the game. This is what I was greeted with.
Relaunched, same thing. Uninstalled and reinstalled launcher, same thing.
Many Windows Store apps will auto-update in the background if your computer is online when a new app version is released. That happened here with the hotfix for WU4