Error 8008 — Invalid child SKU

The child SKU in a variation has invalid data or doesn't follow the expected format.

Child rows missing required variation attributes (color, size), or referencing parent SKU that doesn't match.

1. Each child row needs: parent_sku reference, parent_child='child', relationship_type='Variation', plus the variation theme attributes.
2. Confirm child SKU is unique across the whole feed.
3. Variation attributes (color, size) must match the parent's variation_theme.

• Missing relationship_type on child rows