We get 'sporadic' errors while testing as follows:
Error: There was an error processing your payment: (10536 Invalid Data) The transaction was refused as a result of a duplicate invoice ID supplied. Attempt with a new invoice ID.
We're using FoxyCart with the ExpressionEngine Foxee module. Is this just a glitch in the testing system (PayPal Sandbox?) or something we should be worried about... :?
If this is a result of using the PayPal sandbox for testing is there some way we can work around this? :?