This bug has been fixed.
My Sims kids suddenly are not the parents children anymore but their siblings.
This bug is caused by the cheat cas.fulleditmode.
You can repair the relationships with a few cheats. You can’t remove any values, only overwrite.
First you need the ID of both your Sims.
You will need the following cheats (repeat for each Sim)
- testingcheats true
- sims.get_sim_id_by_name <Firstname> <Lastname>
Write down the number you are given. It’s very long.
Then you can reset your Sims relationships
- relationship.add_bit <ID Sim 1> <ID Sim2> <relationshipBit>
Susan has ID: 775464154248314888
John has ID: 775464154248314999
relationship.add_bit 775464154248314888 775464154248314999 family_parent would now make Susan John’s mother.
How to avoid
Don’t use the cheat on families