This is a first plugin installed in an original OSC v3.8, Bender theme, without any modification.
Plugin configurations:
Paypal Options are both the 'Use standard payment' and 'Sandbox environment' enabled, as well as the 'Allow premium ads' and Credit Packs have also enabled (Pay per post not yet tested).
Problem:
1) This plugin lets you see the ad posted immediately instead redirect you to the page for paying the premium (Users can only purchase the premium from their account)
2) Users can buy the credit pack but the wallet doesn't updated. It says Your wallet is empty after the credit pack purchase.
Other tested versions:
Other earlier versions of the PayPal payment plugin, including the PayPal Plus are also not working. Same problem.
Outcome:
Hope if any experts can help with it, post your code here.