Dynamics AX is a legacy ERP solution that was offered by Microsoft for mid-sized to large organizations beginning in 2008. Mainstream support for Dynamics AX 2009, 2012, and 2012 R2 ended in 2018, and mainstream support for Dynamics AX 2012 R3 will end in 2021. When mainstream support ends, Microsoft will no longer accept support tickets or release feature updates. Once extended support ends in 2021, Microsoft will no longer release bug fixes or security patches! Upgrading to Microsoft Dynamics 365 appears to be the best course of action for businesses that still use Dynamics AX.