Purchase error for no ABN

We import goods from the US and I have always entered these in Purchases, Pay bills.  Normally I get a message saying the supplier has no listed ABN do I want to change the tax code.  I created my own tax code for these suppliers so I say no and then it saves the Purchase.  Today after saying no it comes up with a PurchaseEvent_SupplierHasNoABN warning and when I click OK it has not saved the transaction.

Has something changed in one of the latest updates to cause this, is there a solution or easy work around?

Thanks.