I was using nopCommerce 1.30 and eventually having problem in finding the Shipping Cost for international destinations.
Being unable to upgrade, I have employed the code from 1.50 to 1.30. It was working fine except for the customers in UK. They could see the “Invalid Country” error message. At much of my surprise, when I changed country name “United Kingdom” to “Great Britain” it worked!
Since I think this problem is within the USPS Web Service itself, there is nothing wrong with the nopCommerce Code.
I am not sure about my solution that if it is the only way but it worked for me. I am providing here the code I have changed in USPSComputationMethod.cs [#region international request]:
if( ShipmentPackage.ShippingAddress.Country.Name == “United Kingdom”)