KNative serving is not showing Ready after installing on Openshift - openshift

Question

Followed the link - https://docs.openshift.com/container-platform/4.1/serverless/installing-openshift-serverless.html to install KNative Serving on top of Openshift v4.1. After installing all the openshift operators, control plane. member roll etc as given in the link; I expect to see that serving component is running by executing -
C:\Knative installation>oc get knativeserving/knative-serving -n knative-serving --template='{{range .status.conditions}}{{printf "%s=%s\n" .type .status}}{{end}}'
But the above returns nothing. Just returns back the prompt.
Also below are o/p of the get resource command of the serving component -
C:\Knative installation>oc get knativeserving/knative-serving -n knative-serving
NAME VERSION READY REASON
knative-serving
C:\Knative installation>oc get knativeserving/knative-serving -n knative-serving -o yaml
apiVersion: serving.knative.dev/v1alpha1
kind: KnativeServing
metadata:
annotations:
kubectl.kubernetes.io/last-applied-configuration: |
{"apiVersion":"serving.knative.dev/v1alpha1","kind":"KnativeServing","metadata": {"annotations":{},"name":"knative-serving","namespace":"knative-serving"}}
creationTimestamp: "2020-01-12T10:53:42Z"
generation: 1
name: knative-serving
namespace: knative-serving
resourceVersion: "63660251"
selfLink: /apis/serving.knative.dev/v1alpha1/namespaces/knative-serving/knativeservings/knative-serving
uid: cc4b330f-3529-11ea-83ef-0272cb600f74
What could be wrong? I believe KNative Serving did not install correctly but not sure how to debug. I uninstalled and reinstalled several times but no help.
Also, I thought to proceed and install a service using KNative Serving (ref link https://docs.openshift.com/container-platform/4.1/serverless/getting-started-knative-services.html) but, applying the very first resource shows problem.
service.yaml
apiVersion: serving.knative.dev/v1alpha1
kind: Service
metadata:
name: helloworld-go
namespace: default
spec:
template:
spec:
containers:
- image: gcr.io/knative-samples/helloworld-go
env:
- name: TARGET
value: "Go Sample v1"
Applying service.yaml returns error.
C:\start Knative service> oc apply --filename service.yaml
error: unable to recognize "service.yaml": no matches for kind "Service" in version "serving.knative.dev/v1alpha1"
Any help is appreciated. Thanks.