Important if you upgrade to an newer operating system, make sure and delete afterwards the "windows old" folder. The conflict often arises through old files from the previous operating system.
How do i remove it, follow the Microsoft instructions
http://windows.microsoft.com/en-us/windows-8/how-remove-windows-old-folderMove Options.ini on your desktop and start the game again.
c://Documents/Electronic Arts/The Sims 4
This file can be recreated, including with the new operating system.
Delete all Sims cache files
Be sure that all mods are still compatible with the new operating system!
Good luck and Happy Simming 🙂
Cya
Liz