@krabby_pattiess That's not full enough to prevent the game from saving though. Just in case it's this simple, have you been using the buydebug cheat? The game will often freeze or crash if buydebug is still enabled when you try to save. There's nothing wrong with using it; just remember to disable it when you're done.
Otherwise, as a test, please move the entire Sims 3 folder out of Documents > Electronic Arts and onto your desktop. When you launch the game, a clean folder will spawn with no content. Don't add anything to it yet; just start a new save and see whether you can save your progress without crashing.
If the new save crashes too, please temporarily disable the iCloud syncing of Documents and see whether it helps. If the new save does NOT crash, please copy your existing save to the new Sims 3 folder and see whether it can save. Don't move over any other content with the exception of a store or custom world if the save takes place in that world.
Let me know the results, and we'll go from there.