Error 13603 — Key features missing

Category-required key feature attributes are missing — for electronics, this might be wattage; for apparel, fit_type; for books, format.

Each category has its own list of 'key product features' that must be populated. Generic feeds skip them.

1. Pull the Category Listings Report from Seller Central for your category.
2. Identify the required 'Item Specifics' marked as required.
3. Populate each in the feed.
4. Resubmit.

• Treating optional fields as truly optional when they're required for some categories