Shippo returned no rates for the parcel/address combination. Common causes: the Carrier Whitelist filters out every carrier that serves the address, no carriers are connected in your Shippo dashboard, the Parcel Template is invalid or inactive (Shippo: The selected Parcel Template is invalid or inactive. Please go to Integrations > Shippo and re-select a valid template.), or the address/weight is outside what the carriers accept. Use Run Test Calculation on the integration card to see the raw response.