Quote Originally Posted by arensun View Post
Error We are sorry for the inconvenience. The PayPal account in this store is presently misconfigured to use mixed sandbox and live settings. We are unable to complete your transaction. Please notify the store owner so they can correct this problem. (10002)
Code:
PayPal IPN     paypal     0          default    
PayPal Express Checkout NOT CONFIGURED YET     paypalwpp     0          Processing
The error message and the "NOT CONFIGURED YET" message both indicate that you haven't fully configured the PayPal Express Checkout module ... specifically, the API credentials haven't been entered properly.

See here for some instructions in addition to those provided in the admin area: http://www.zen-cart.com/getpaypal