Unable to mutate Life Event criterion to Display ad group

[Jamie Addessi]

I'm having trouble with the Google Ads API (v21) when I try to add Life Event Criterion to an Ad Group on Display Campaigns.
I've tried adding the same criterion through the UI and it succeeds, but when I try to add the criterion in the API I get the following error:

{
  "errorCode": {
    "criterionError": "UNKNOWN"
  },
  "message": "The error code is not in this version.",
  "trigger": {
    "int64Value": "95005"
  },
  "location": {
    "fieldPathElements": [
      {
        "fieldName": "operations",
        "index": 0
      },
      {
        "fieldName": "create"
      },
      {
        "fieldName": "life_event"
      },
      {
        "fieldName": "life_event_id"
      }
    ]
  },
  "details": {
    "unpublishedErrorCode": "CriterionError.INVALID_LIFE_EVENT"
  }
}

Is this feature is supported in the current version of the API? If so, why this error?