In order to resolve this error, you will first need to determine what you using for your "CONTACT NAME FORMAT". To find this, go to your Xero configuration page in the Recurly UI. Once you have determined what you're using as Contact Name Format, go the account page for the customer experiencing the error and populate the empty field.
For example, let's say you have chosen "Account Company" for your Contact Name Format. The accounts with "name: can't be blank" error will be for accounts that do not have a company name. If you populate a company name on these accounts, they will sync over.