I am using 'Gravity forms AWeber Add-on" and tried to add API credentials generated from https://auth.aweber.com/1.0/oauth/authorize_app/2ad0d7d5 number of times, but no luck so far. It always shows red-symbol (Invalid API Credentials. Please try another.) under AWeber settings.
WordPress version: 3.5.1
Gravity Forms version: 1.6.12
Gravity Forms AWeber Add-on version: 1.3
Any quickest help would be highly appreciated.