Knative supports upgrading by a single minor version number. For example, if you have v0.21.0 installed, you must upgrade to v0.22.0 before attempting to upgrade to v0.23.0.
To verify the version of your current Knative installation:
Check the installed Knative Serving version by entering the following command:
kubectl get KnativeServing knative-serving --namespace knative-serving
NAME VERSION READY REASON knative-serving 0.23.0 True
Check the installed Knative Eventing version by entering the following command:
kubectl get KnativeEventing knative-eventing --namespace knative-eventing
NAME VERSION READY REASON knative-eventing 0.23.0 True