The following error messages can be generated by get_payments_on_invoice_m.
1001: unexpected error
1004: authentication error
Associated Inputs: auth_key, client_id, client_no
1009: account does not exist, Account not found: AriaNo (acct_no), Account not found: Userid (userid), or Account not found: ClientId (client_acct_id)
Associated Inputs: acct_no, account_no, client_acct_id, user_id, userid, parent_acct_no
2001: transaction does not exist
Associated Inputs: invoice_no
1008: no line items provided
Associated Inputs: invoice_no
Additional Comments: There are no payments on the invoice.