We've had a 5.09.06 working on a site for about a year just fine. Beginning July 30 it suddenly stopped working with Authorize.net and brings a 103 error with each attempt to check out. I've been on the phone with AN and nothing has changed on their end.

We did a back up restore of our site to July 27 and the same result. On July 27-29 all orders processed fine and we are now exactly as it was when working before. We did a re-issue on the Transaction Key twice, same deal.

I'm stumped. Non working cart that normally does 10k + a month or more. Owner has been kind so far but...

Any ideas?