Have member site. Using the following:
Paypal (Free Business account)
To join the site it is a one time $97 payment. That part works perfectly.
When I set up a $1.00 7 Day Trial with one time $96 auto billing I get the following error message when I try to buy:
"Payment error: An internal error happened in the script, please contact webmaster for details"
If I turn auto billing off then it works.
I can see amember is trying to handshake with PP when the error occurs.
I went through the amember documentation and set PP up like it says it needs to be.