I've received this error and have no possible solutions on how to resolve it. I've tried multiple sandbox accounts and verified the testing Login ID and Transaction Key match. The console shows that the request is going to the test environent (apitest.authorize.net) rather than live environment, so it doesn't appear to be an issue posting to the wrong environment. Checking for the above seems to be the only solution/suggestion I've found so far. If not an issue with the credentials or the environment, why else could I be receiving this error?
Thanks,
Austin
