When I use digital goods (express checkout) on sandbox, everything runs ok, but when I try to use under production gives this error:
"You are not signed up to accept payment for digitally delivered goods.".
on my panel paypal don't find that configuration.
You can sign up for the digital goods at below link :
https://www.paypal.com/webapps/mpp/digital-goods
In case in doesn't work you need to contact the PayPal support to enable it on your account .