We've been using the authorize.net payment method plugin provided by the NopCommerce dev team just fine until last Thursday, when out of the blue we started getting credit card authorization timeouts on every order. On each and every order, the customer's card is authorized, but the order doesn't go through - it errors out with an error that says "The operation has timed out." The stack trace identifies the part of the plugin where it calls "GetResponse" and is (presumably) waiting on a response from Authorize.net. I tried using the other free authorize.net plugin, but ended up with the same result. I called authorize.net, but they said I needed to contact the software vendor for help; they don't get into troubleshooting "software integration issues".
This is so terrible, our site is down during the Christmas season. Any idea what could be causing this?
We're using Nop 3.8.