A required value is missing for the specified variation theme
A required value is missing for the specified variation theme: [Message/Product/ProductData/ClothingAccessories/VariationData/Size = null], [Message/Product/ProductData/ClothingAccessories/VariationData/VariationTheme = "Size"].
This kind of error might appear when you send new Amazon listings with variations. The error means that the Shopify product does not have efficient data for the variation theme selected in the Creation Profile. For example, Variation Theme might be ColorSize but Shopify product has variations only in color.
You should adjust the variation theme for the selected products. Another option might be adjusting variations on the Shopify product page. It depends on what works better for the specific product.