Invoices "Needs Revalidation" when we change AWT Code

 Dear All,

Our client requirement is that they select AWT code on invoices at the time of invoice Booking it will come from the supplier form. It is normal practise the booked invoice payment was not occur in the same period. Final invoice accounting has been done but the payment made in the next period. Issue is that when they found that the AWT Code was not correct and change in next accounting period than invoice goes on "needs revalidation" and couldn't change the status to validate the invoice.

Payable option is set creation of "AWT invoices at the time of payment".