Ah, I suspect this is a compatibility issue with MC Woohoo and possibly Wicked Whims, then. Most likely they're trying to change some of the pollination coding that I've tweaked. I can try redesigning some parts of this to get around MC Woohoo's intended changes, but because that's all in Python I have limited visibility into exactly what's going on. I don't use either of those so didn't run into any issues.
Viewing post in v3.7 Update - Alien Pollination and Expanded Fears comments
Good news is that this was a feature update, so you're safe rolling back to v3.62. If you've deleted that, it's still available on Nexus under old versions: https://www.nexusmods.com/thesims4/mods/2342?tab=files