@molb18 Does your computer have a 12th-gen or newer Intel processor? If so, you'd need a workaround to get the game running at all, which you would likely know since you did successfully play once. But perhaps you're not aware that some workarounds need to be used every time, or perhaps the EA App repaired the game and reverted the effect of the Alder Lake patch. Point is, if you do have one of these processors, please apply one of the relevant workarounds:
https://answers.ea.com/t5/Technical-Issues-PC/Sims-3-won-t-open-Alder-Lake-Intel-12th-gen-CPU/td-p/11057820
If that's not the issue, try forcing the game to launch in windowed mode. Go into Documents > Electronic Arts > The Sims 3, open Options.ini, search for fullscreen , and set it to 0 (zero).
If that doesn't help, please run a dxdiag and attach it to a post.
https://help.ea.com/en-us/help/pc/how-to-gather-dxdiag-information/