So, right at the beginning of doing the Cozy Celebrations event, not one, but both my Sims in my household got munched on by the cowplant, and they both got the "Fear of the Dark" trait, among other ...
Ideas
It seems the fix for this didn't fix existing save games. You'll need to fix it manually.
More details see this: Sim Gets Fear of the Dark After Being Cured | EA Forums - 12297500
