I have recently upgraded to 1.3.8a, so I can take advantage of the PayPal Website Pro credit card payments system. I have been using PayPay Express and Credit Card Payments off line with PayPal's Virtual Terminal through a Website Payments Pro account.

After the upgrade and installation of the PayPal Website Payments Pro (I re-installed Express too), I received this message on my test purchase.

10501 Invalid Configuration - This transaction cannot be processed due to an invalid merchant configuration.

Since I have been using PayPal Express and Virtual Terminal successfully, I do not understand why I am receiving this message. I have reviewed my PayPal set-up and it seem OK.

Could someone please help me?

Thank you,
Katrina