Void option on Payment actions screen is disabled while trying to void a payment

Void option on Payment actions screen is disabled while trying to void a payment.

Oracle application R12 (12.2.5)

The payment is done for a prepayment and the prepayment is already applied to a standard invoice.

Oracle actually restrict voiding a payment for a prepayment already applied to an invoice

To void the payment 

Go to prepayment applications and un-apply any invoices applied

Query for the invoice to which you have applied the prepayment (now the invoice should have new distribution line and status must have changed to ‘Needs re-validation’)

Validate the invoice and create accounting

Go back to payment screen and query the payment you want to void

Click the Actions Button

Void check box should be enabled now