Quick answer: Unity Prefab Variant overrides reverting after save / play? You may have applied the override back to the base, or the variant’s reference path is corrupted.
A team member edits a variant’s color tint; on save the value snaps back to the base prefab. Either the change auto-applied to the base or the override link is broken.
Apply vs Override
The Overrides dropdown has Apply (writes to base) and Apply as Override in Prefab Variant. Hitting Apply by mistake propagates the change to base, then removes the override entry — variant looks “reset” against the new base.
Inspect Overrides
Click the prefab in scene → Overrides dropdown shows every override. If your expected override isn’t listed, it was never recorded or got reverted.
Property Modifications Array
Variants store overrides in a m_PropertyModifications array in YAML. A corrupt array (truncated, duplicate entries) can drop overrides on save — verify YAML integrity.
Verifying
Set a value on the variant, save, restart the editor — value persists. Overrides dropdown shows the entry.
“Variant overrides require an Override entry. Don’t Apply to base by mistake.”
Lock the base prefab when handing variants to designers — m_IsLocked in YAML prevents accidental Apply that nukes everyone’s overrides.