Container Service for Kubernetes (ACK) no longer supports Kubernetes 1.12.6 and earlier based on the support policy for Kubernetes versions. ACK also ends technical support for Kubernetes 1.12.6 and earlier. We recommend that you upgrade Kubernetes versions for your ACK clusters as soon as possible. For more information about how to upgrade a cluster, see Upgrade a cluster.
For more information about the support policy for Kubernetes versions, see Kubernetes versions.