I have a Windows 10 computer and just got a new disk of The Sims 3 (I had an older disk that did the same thing so I think it may be the computer) as well as the Seasons expansion, Late Night expansion and High End Loft stuff pack. Anyway, there's a flicker sort of thing that seems to show the lower "layers" of the screen. So, if it's the loading screen after the main menu, it'll show the overview of Sunset Valley that comes after that loading screen. When it first starts it's at the top of the screen but as I continue it will spread to the bottom, but I've never played long enough for it to just completely flicker on the whole screen. I couldn't find anything on The Sims 3 forums, the EA website, the Steam forums or other websites. I've adjusted the graphics but it doesn't make it better. It only starts in the first loading screen, not in the little video before. And finally, it only happens in full screen mode.