Customer is trying to import new customer payments without applying any invoices. However, in the Field Mapping page, Invoice (Req) and Payment (Req) fields are automatically mapped and there is no way to remove as the 'x' mark as these are being greyed out.
1. Verify if the CSV Import File uses column header for Amount.
Note: If so, change the column header from Amount to Payment Amount.
2.The system is automatically mapping the Amount field to Invoices : Payment (Req) field.