This was causing the following error when applying the channel:
I0429 09:05:44.828460 15185 apply.go:71] configmap/spotinst-kubernetes-cluster-controller-config unchanged
secret/spotinst-kubernetes-cluster-controller-certs unchanged
serviceaccount/spotinst-kubernetes-cluster-controller unchanged
clusterrole.rbac.authorization.k8s.io/spotinst-kubernetes-cluster-controller unchanged
clusterrolebinding.rbac.authorization.k8s.io/spotinst-kubernetes-cluster-controller unchanged
deployment.apps/spotinst-kubernetes-cluster-controller configured
error: error validating "/tmp/channel152526040/manifest.yaml": error validating data: [apiVersion not set, kind not set]; if you choose to ignore these errors, turn validation off with --validate=false
Error: error updating "spotinst-kubernetes-cluster-controller.addons.k8s.io": error applying update from "s3://REDACTED/kops/REDACTED/addons/spotinst-kubernetes-cluster-controller.addons.k8s.io/v1.9.0.yaml": error running kubectl