[LS] Sim who has never been heartbroken died of broken heart

May I ask what that means? Thank you.

Lovestruck - All of my poly Sims (all not jealous boundaries in CAS, + "Player" achievement, many have Romantic Sage trait) have broken hearts since I've played Lovestruck. No one broke their hearts. They can't even seriously flirt with their household partner (other parent of their children) without getting the sorrow moodlet or dying. (None of my Sims are married, engaged, girlfriend/boyfriend, etc). I am keeping my Sims loveless; no flirting, no woohooing. This spoils the game somewhat for me. An idea I have for the developers is to make a "cure broken heart" potion available in the Sims' Reward Store. That way all my Sims could buy it, drink it, and perhaps go about their lives as usual. (I know I can add a child to the family in CAS, but it would be nice if one could make one the old-fashioned way.) I've got over 100 Sims of child-bearing age. Can someone help me? What am I missing?

This is a bug.  moving your mods around and deleting the cache won't make a difference.  There are a heap of bug reports about this on the EA page.  

Move your Mods folder to the Desktop and delete localthumbcache.package. Then test the game in a new save.
If it works now check for updates to your Mods and CC. Add it back a little at a time while testing until you have found all that are broken.