Creating a sims or editing a sims

EllenGameer  Please test with no mods or custom content, if you haven't already.  Move the Mods folder to the desktop and delete localthumbcache.package.  You don't need to save your progress.

If this doesn't or didn't help, please try playing in a clean user folder.  Move the entire Sims 4 folder out of Documents > Electronic Arts and onto your desktop.  When you launch the game, a clean folder will spawn with no content.  (Your saves and other content will be intact in the folder you've moved but temporarily unread by the game.)  Don't add anything to the new folder yet; just start a new save and test CAS a few times.