As you may be aware, Authorize.NET is enacting API Changes which affect Active Commerce customers who utilize the Authorize.NET payment provider. These changes are already in effect in the Authorize.NET sandbox environment and will go into effect in production on June 28, 2019.
Active Commerce is providing an updated version of the Authorize.NET Plugin to customers utilizing Authorize.NET for payment processing. We recommend thoroughly testing the updated plugin in your own test environment. To ensure you receive an updated plugin, please submit a ticket with your Active Commerce Version and Sitecore Version.