We are setting up our Paypal environment to make some recurring payments and made our sandbox environment as well. We did the following on the sandbox:
1) Created our paypal account business and 3 different buyer accounts and verified them.
2) We created the billing plan and the subscription button and embedded it in our webpage to test it.
3) We used our buyer accounts to try it out and make the subscription (everything is verified already: cards and emails).
Everytime we try to finish this, we always get the "Sorry we weren't able to set up preapproved payments at this time" every time. With all the users, even in sandbox and in our live server (we made the charge be 10 MXN to test it out and tried to pay with my real paypal account)... Not sure what to do next.
