taylerbeale That sounds like this known issue:
https://answers.ea.com/t5/Bug-Reports/OPEN-LS-Infinite-Loading-Screen-After-Planning-Date/td-p/13896504
I don't know of a fix at the moment, but you can keep an eye on that thread for suggestions or updates.
xladycoffeex and JustLonnieK CAS stuck loading is currently mostly mod-related. Please see the accepted solution of this thread for mods known to cause this:
https://answers.ea.com/t5/Mods-CC-Issues/CAS-infinite-loading-screen-after-23-07-update/td-p/13898789
If you don't use mods, or removing them doesn't help, try a clean user folder. Move the entire Sims 4 folder out of Documents > Electronic Arts and onto your desktop, and when you launch the game, a clean folder will spawn with no content. (Your saves and other content will be in the folder you've moved but temporarily not read by the game.) Don't add anything to the new folder yet; just test out CAS.
If the new folder works, you can transfer your saves, Tray files, UserSettings.ini, and maybe Screenshots or Recorded Videos from the old folder. But test your mods and cc first, and update or get rid of anything that makes CAS stop working again.