kube-dns is invalid

This error typically occurs when there is an issue with the kube-dns service in your Kubernetes cluster. It could be due to misconfiguration or an issue with the deployment itself.

To troubleshoot the issue, you can try the following steps:

1. Check the logs of the kube-dns containers using the `kubectl logs` command. This can help identify any errors or issues with the service.

2. Verify that the kube-dns service is running by checking its status using the `kubectl get svc -n kube-system` command.

3. Check the configuration of the kube-dns deployment and ensure that it is correctly configured.

4. If the above steps do not resolve the issue, you may need to recreate the kube-dns deployment from scratch.

It's also worth noting that kube-dns has been deprecated in favor of CoreDNS, so you may want to consider migrating to CoreDNS if you haven't already done so.