No List of Values for Payment Terms in Customer Account Profile Window in Oracle R12

Check the payment term Billing Cycle Control or not.

Receivables Manager>Set Up > Transactions> Payment Terms ( Check Billing Cycle column)

select cycle_name,billing_cycle_id,name from ra_terms_vl

Even if yes or no then please try as below.

Receivables Manager> Customers > Customers

Query the customer concerned

Tab: Account Profile

Uncheck the 'Enable' check box under 'Balance Forward Billing' under Account Profile Tab and then check the payment terms should be now visible.