Re: sims 4 stuck on white screen and will not close

@Kidothewolf  Can you bring up the Task Manager?  Click crtl-alt-delete and select the TM, then select Sims 4 and End Task.

If that doesn't work, you can crtl-alt-delete and log out rather than restarting.  This will force-quit all running applications, so you'll lose any open work you have, but when you can't access the Task Manager, that's really your only other option.  It might be possible to alt-tab to anything else running and save your work though.

And it sounds like you added one or more broken mods, so it's a good idea to remove whatever you just added before trying to play again.