Menu flickers with dark sections appearing.... what's going on

The potential cause for it was correlated to NVIDIA drivers (happens on some while not on others). Make sure your drivers are up-to-date. If it doesn't work you can launch the game using -oldgameui instead. ^_^

Originally posted by CattoCult:

The potential cause for it was correlated to NVIDIA drivers (happens on some while not on others). Make sure your drivers are up-to-date. If it doesn't work you can launch the game using -oldgameui instead. ^_^

but what if want the new shiny UI?

https://steamcommunity.com/app/362890/discussions/5/3006676913238913730/
this should help