Istio Manifest Issues When Upgrading from 1.5.4 to 1.6.2

Hi,

I am working on upgrading Istio from 1.5.4 to 1.6.2. Our existing manifests are failing with unknown fields. Examples Below:

./istioctl manifest apply -f …/…/manifests/istio-svc-virtual-services.yaml
Error: failed to apply manifests: unknown field “http” in v1alpha1.IstioOperatorSpec:

./istioctl manifest apply -f …/…/manifests/istio-public-ingress.yaml
Error: failed to apply manifests: unknown field “minReplicas” in v1alpha1.IstioOperatorSpec

failed to unmarshall mesh config: unknown field “concurrency” in v1alpha1.MeshConfig, unknown field “dnsRefreshRate” in v1alpha1.GlobalConfig

What has changed in-between 1.5.4 and 1.6.2 have these fields been deprecated?, do I need to reformat my files or move away from the v1alpha1 API?

Thanks