Bug Report – Family Relationship Automatically Changes to Siblings After Update

Game: The Sims 4

Game Version:  Feb 4 2026

Platform: [PC / Mac]

Mods Installed: Yes (**bleep** – updated to latest version)

Issue Description

After updating the game, two Sims who were previously romantic partners (not related by blood) were automatically flagged as siblings in the genealogy panel.

Before entering Live Mode, everything appeared normal in CAS. However, once entering Live Mode, the relationship changed and they were marked as siblings.

I attempted the following:

• Updated all mods to the latest compatible versions

• Removed all mods and tested without them

• Cleared localthumbcache.package

• Recovered previous save versions

• Saved affected Sims to the Gallery and replaced them

The issue still reoccurs in the same save file.

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Expected Result

The Sims should retain their original romantic relationship and not be reassigned as siblings.

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Additional Notes

This issue began immediately after a game update.

It appears that the family relationship flags are being reassigned or recalculated incorrectly upon loading the save.