Re: New world won’t load

@eilidh2004  Please clear Origin's cache:

https://help.ea.com/en/help/faq/clear-cache-to-fix-problems-with-your-games/

and repair the game: open your Origin game library, right-click on the Sims 4 icon, and select Repair.

If that doesn't help, move your entire Mods folder to the desktop, delete localthumbcache.package, and test.  Please try a new save as well as your existing ones.