ControllerConfig.machineconfiguration.openshift.io "machine-config-controller" is invalid: [spec.imageRegistryBundleUserData[0].data: Invalid value: ""

Issue

• The Machine Config Operator becomes degraded, and the following error is logged in the machine-config-operator pod
• Upgrade stuck due to machine-config CO degraded

2025-04-29T18:58:22.454248405Z I0429 18:58:22.454186       1 event.go:298] Event(v1.ObjectReference{Kind:"", Namespace:"openshift-machine-config-operator", Name:"machine-config", UID:"xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxx", APIVersion:"", ResourceVersion:"", FieldPath:""}): type: 'Warning' reason: 'OperatorDegraded: MachineConfigControllerFailed' Unable to apply 4.14.50: ControllerConfig.machineconfiguration.openshift.io "machine-config-controller" is invalid: [spec.imageRegistryBundleUserData[0].data: Invalid value: "": spec.imageRegistryBundleUserData[0].data in body must be of type byte: "", <nil>: Invalid value: "null": some validation rules were not checked because the object was invalid; correct the existing errors to complete validation]