Annilou62 If you have any files in ConfigOverride, please delete them.
Otherwise, try playing in windowed mode instead. (This is a test, not necessarily a fix.) If you can't open the Options menu to switch while in-game, you can open Options.ini, in Documents > Electronic Arts > The Sims 4, search for fullscreen , and set it to 0 (zero).
The idea is that another app might be capturing your clicks, so to speak, not allowing you to click inside the game window. Running Sims 4 in windowed mode gets around this some of the time, but if it doesn't help, you can try playing with all other apps closed, after restarting your computer.