Hiya! Thanks so much for your insight. I think I'm getting closer to solving the issue.
I took out all my script-related mods, went to edit a sim in CAS with the cheat, and it happened again. I'm not sure what I should try next?
If you're sure that you've removed all script mods then try creating a test file just to verify that the problem isn't patch related. Rename "My Documents\Electronic Arts\The Sims 4" to "The Sims 4 - Backup" then re-launch the game and try editing another sim. If the problem does not occur then you must have another script mod. You should also try disabling script mods under Game Options - Other.
