An administrator is updating a VMware vSphere Kubernetes Service (VKS) cluster by editing the cluster...

The documented behavior of kubectl edit is that it opens the object manifest in a local text editor, and the editor it launches is controlled by environment variables. In the VCF 9.0 documentation (Workload Management / Supervisor operations), the procedure explicitly states: “The kubectl edit command opens the namespace manifest in the text editor defined by your KUBE_EDITOR or the EDITOR environment variable.”

If the administrator’s environment does not have KUBE_EDITOR or EDITOR defined (or they point to an invalid/interactive-less editor in the current session), kubectl edit may not open the expected editor workflow, and the admin may not see the normal confirmation after saving and exiting. Setting KUBE_EDITOR (preferred for kubectl-specific behavior) or EDITOR ensures kubectl launches a known-good editor, allowing the manifest to be modified, saved, and then submitted back to the API server when the editor exits. The same documented requirement also applies to editing other Kubernetes objects (such as a VKS cluster manifest) because the kubectl edit mechanism is identical.