@imen19 ... You seem to be right...I can't verify because I uninstalled Avast along with any quarantined game files! Now I persistently get this launch failure now no matter what I do. So, before uninstalling and reinstalling my game again, I decided to let Steam verify my game files and sure enough it found 1 file missing (the ts4.exe file?). So,now I have my missing file back I can get the Sims to launch again. Thanks for this information, it seems to be the fix for Avast users.
Came to find out that my Antivirus was blocking my Sims File and it was being quarantined. I had to find it and restore it. Also put an acceptance.
