Sims 3 Suddenly Won't Launch Windows 11

What you're running into is a bug with the launcher and Windows 11.  There's a workaround for it; it's a bit of a PITA (you have to do this EVERY time you want to launch the game), but it's doable.

After you launch the Launcher, and you see the big PLAY button, do NOT click it; go to Task Manager (Control-Alt-Delete => Task Manager), and click the Details tab on the left.  Then scroll down to Sims3Launcher, right-click it, and select "Set affinities".  Now turn off ALL CPUs except for one (I usually turn off all of them, and then turn on CPU 0) for the launcher.  Do not close Task Manager; you will need it again in a moment.  

Now go to the Launcher, and click Play.  Wait until you see the game start up (for me, it's seeing the green plumbob icon on my taskbar, even if the splash screen hasn't appeared yet), then switch back to Task Manager.  Now scroll down to the TS3.exe (it may be called something different if you run Sims 3 from Steam), right-click it, select "Set affinities", and turn all of the CPUs on again.  

I had this problem when I bought my really powerful gaming rig about a year ago, which happened to come with Windows 11.  I tried for months to get the game to work, and finally gave up and resigned myself to playing Sims 4.  Then the Sims YouTuber Pixelade came out with a video on this a couple of months ago, which was very enlightening.  I haven't gone back to Sims 4 since, and I don't know that I ever will.