I followed all the directions I saw on both the nopCommerce and PayPal web sites about setting up this payment method. On the shopping cart, when I hit the Confirm button, I get this error message:
LongMessage: Security header is not valid ShortMessage: Security error ErrorCode: 10002
What does this mean, and how do I fix the problem?
Are you in the sandbox? if so is goes up and down and can be unstable; and you can think you did something wrong when it's sandbox misbehaving. If not then you just need to retrace your steps because nopComm and Paypal both work.
