@tmwheels Delphy's Dashboard doesn't flag all bad custom content. And the fact that you don't have any conflicts only means that the mods and cc don't conflict with each other, not that they all work properly. This still sounds like bad cc, probably something a sim somewhere in the world is using for a trick-or-treating costume. When the sim attempts to change into that outfit, the game crashes.
As a test, remove all your custom content, load the affected save, and see whether the sim kids can trick-or-treat. (Don't worry about missing items, since this is just for testing and you don't have to save your progress.) If the game doesn't crash, then you know it's bad cc, and you'll need to sort through your content. Let me know if you need help with this.
