When migrating orders from WooCommerce to Shopify the app will migrate the shipping and billing addresses if present. In WooCommerce the first and last name fields for addresses are not required, however Shopify will reject the address if the first and last name are not present.
To fix this, first and last names in the shipping and billing addresses will be set to a period if there is now value in the WooCommerce API. (We tried a single space character but that didn't work.) This is needed for Shopify to accept the address.