I am using NopCommerce 3.7, SQL Server on our own web servers.
We have a store (poserworld.com) that is primarily 3D model downloads (and a few DVD's), we use Authorize.net and now PayPal Standard. We were using the PayPal express plugin previously as we have more than one store that uses PayPal and we were afraid that using the IPN stuff would cause a problem with our Poser World store.
Well the PayPal express plug defaulted to Afghanistan as the first country so if someone used PayPal express the "shipping" address would have Afghanistan. All fine and good until you move to the builtin PayPal standard plugin.
Evidently Afghanistan is blocked at PayPal
Here is PayPal's list of countries, note that Afghanistan is not listed
<https://www.paypal.com/webapps/mpp/country-worldwide>
Even though we don't have shipping enabled on the 3D model downloads, when someone used the PayPal standard method and have the country Afghanistan already listed in their shipping address (or I assume billing as well), it triggers a failed order due to PayPal not allowing Afghanistan.
If you go into the order that is causing problems and change the country to other than Afghanistan the PayPal method works as it should.
Not sure if this counts as a bug or an issue, but perhaps the plugin should detect that error and offers the person to edit their order and change the country, or not allow PayPal countries out of the box.