We have been running with Authorize.net for long while now. This past January I setup ARB for membership renewals, and it was working great. We have numerous ARB subscriptions since then. Then, 2 weeks ago, they stopped working.
The membership transaction processes in Authorize.net, but it does not create the ARB subscription. Also, the contribution in CiviCRM stays at Pending, and never is moved to Completed.
The setup in Authorize.net hasn't changed. The Silent Post URL is set properly. Other non-ARB transactions are working properly.
I am at a loss as to what has happened to cause this to stop working. Does anyone have any thoughts on this? Any ideas would be appreciated.
CiviCRM 4.7.8, Joomla 3.5.1