I'm stuck with an annoying issue. One Rancher managed cluster is constantly in error state with message

secrets "cattle-system/c-c-xrj24" not found

I can still access the cluster and everything is running correctly, but I cant e.g. update kubernetes version. I've tried to figure out what that secret should contain, but all my attempts end with "handler cluster-provisioner-controller: unexpected end of JSON input". E: Does anyone have an idea how to fix this, e.g. recreate that secret? What that secret should even consist of?