I'm installing a new copy of OSC 2.3.1, with no addons. I am trying to get the payment module to authorize.net to work properly, but for some reason my response from authorize.net is not being received. I've tried both methods AIM and SIM. The order does go thru authorize.net successfully, but the response is not being received by the store and the order is not updated as complete.
In the case of SIM, I am returned to the login page, after post payment, and I am no longer logged in. For AIM, I get a general return error saying the credit card was not processed, but infact it was.
Any help would be appreciated.