Shopify found a row with option values but no parent product to attach them to. This happens when the first row of a product has an empty Handle while later rows of the same product do not.
Build the file in Shopify's own column order and never sort it before import. Sorting separates a product's rows and breaks the parent-child relationship.
The free Shopify CSV checker names the exact line for each of these problems. The paid Rescue Kit adds 20 more error cases, a template in Shopify's column order, and the checker as a script you can run in a pipeline.
See the Rescue Kit →