Transactions CSV Import > Error: You must map one of the following NetSuite fields to a column in your CSV file, to be a unique identifier: External ID, Internal ID, or a transaction number field, such as Order # or Invoice #.

New transactions are being created through CSV Imports and the error has been encountered after clicking Next on the Field Mapping page.

To be able to go through with the import of new transactions, at least one of the fields (External ID, Internal ID, or a transaction number field, such as Order # or Invoice #) should be mapped on the Field Mapping page in order to uniquely identify transactions.