Follow the below steps to resolve the error:
Go to Distribution, 58. Statement of distribution.
Complete the Residential address for individuals or Business address for non individuals for all the beneficiaries.
Leave the Country field blank for Australia.
Ensure you have entered the country code (overseas address).
Confirm correct spelling of the country (overseas address).
If the correct spelling of the country is confirmed, go through all the beneficiaries and retype the country field in Beneficiary details tab.