In the Adagio Receivables sample data, there are a number of sample CSV files that contain examples of invoices (with and without JC info), debit/credit notes, and cash payments. All of these samples are based on the Default templates so you do not have to modify any of the field layouts.

You may also want to print out the import template you are currently using to import your invoices, in order to compare the fields and data types of your import file(s).

Regards,