Just FYI, in case any of your merchants contact you about this:
Currently there is a system issue that is causing some merchants to receive an error with their approved transaction response. This error does not reflect the actual transaction status. Please tell your merchants to NOT re-run the transaction as this may result in their customer being double charged and their account to be double billed. We are working to resolve this issue and apologize for any inconvenience. We will follow up with more information as it's available.
Developer Community Manager