We have running instance on GKE. Till this afternoon we started to receive "x509: certificate signed by unknown authority" error from new created kubernetes cluster. The kubectl is working with old clusters but not with new ones.

What we tried:

• gcloud update
• kubectl update
• gcloud re authenticate
• clean gcloud install & auth
• .kube/config cert remove & gcloud container clusters get-credentials
• remove and add new clusters

Thanks.