Failed to parse network config: error parsing Network Attachment Definition: unexpected end of JSON input

Issue

• after upgrading the CNI from SDN to OVN following error shows up in the events

  • OpenShift 4.19

    Warning   InvalidConfig       /<nad-name>              Failed to parse network config: error parsing Network Attachment Definition namespace/<nad-name>: unexpected end of JSON input
    

  • OpenShift 4.16

    addLogicalPort failed for <namespace>/<pod>: failed to update pod <namespace>/<pod>: Operation cannot be fulfilled on pods "<pod>": the object has been modified; please apply your changes to the latest version and try again
    

• after upgrading the CNI from SDN to OVN following error shows up in the ovnkube-control-plane logs

  • OpenShift 4.19

    Failed to parse network config: error parsing Network Attachment Definition <nad-name>: unexpected end of JSON input
    

  • OpenShift 4.16

    cluster-manager: net-attach-def <namespace>/<nad-name> is first seen and is invalid: error parsing Network Attachment Definition <namespace>/<nad-name>: unexpected end of JSON input