Unable delete unposted standard voucher

Hello Team,

Working on India Localization E920.  I am not able to delete the Standard Voucher. 

Followed the below steps -

-I have entered the standard voucher.

-calculated the Tax (R75I515) prior to posting the batch.

- make the payment(Net of Tax) post the payment batch

-Voided the payment.Post the batch

And want to delete the standard voucher. I am interacting with below Error while deleting the voucher -

At least one voucher could not be voided 

A form level error has occurred.
CAUSE: At least one voucher was not voided because:
  a) The voucher is partially paid, or
  b) The voucher is not posted and it has a document associated with it.