I've had my first error, can't start on my Sims 4 game in over 6 years and it is all Windows 10's fault not Maxis (unless they sort it out with them. I've updated to the latest one this week.
You have to allow Windows Defender to allow the what it calls an App. through and if you go to the Windows Defender settings you'll Virus & threat protection
Virus & threat protection settings
Controlled folder access
Allow an app through controlled folder access
then + Add an allowed app
and if you are lucky you'll find TS4_64.exe already there
and just add it
Found something about this in Windows Answers but this has only happened to me today.
Good luck Simmers. I'm getting so fed up with Windows 10 updates but it's sure keeping my mind alert!