Authorize.Net issued an email to all Authorize.Net developers notifying us that they are changing the way that you access the Authorize.Net service. This will only affect Dynamics AX2009 users that are still using the Authorize.Net credit card interface. Please read the complete details at the Authorize.Net notice below:
http://app.payment.authorize.net/e/es.aspx?s=986383348&e=913196&elq=1eddcf0cddc4460ba4abb994d7435b1e
To change your settings, modify the URL on the Credit Card Processors form to conform to the new settings listed in their notice in the section entitled “Updating your solution”.
The old setting was https://secure.authorize.net/gateway/transact.dll.
The new setting would be https://secure2.authorize.net/gateway/transact.dll.
Note that, according to Authorize.Net's notice, you can make the change immediately. We recommend that you make the change as soon as possible and test the new URL before the older URL no longer works starting in June 2016.