Got "Unknown plugin name: aws:createImage" while creating SSM Document

Question

I would like to create an SSM document for scheduling weekly backup AMI images, I have tried to copy the content from the built-in AWS-CreateImage document and made a few quick modifications to meet my requirements, but I couldn't pass the examination and keep getting this error message:

InvalidDocumentContent: Unknown plugin name: aws:createImage

Here is the content of my customized document:

{
  "description": "Creates an AMI image from an EC2 instance",
  "schemaVersion": "2.2",
  "assumeRole": "{{ AutomationAssumeRole }}",
  "parameters": {
    "InstanceId": {
      "type": "String",
      "description": "(Required) The ID of the Amazon EC2 instance."
    },
    "NoReboot": {
      "type": "Boolean",
      "description": "(Optional) Do not reboot the instance before creating the image.",
      "default": true
    },
    "AutomationAssumeRole": {
      "type": "String",
      "description": "(Optional) The ARN of the role that allows Automation to perform the actions on your behalf. ",
      "default": ""
    }
  },
  "mainSteps": [
    {
      "name": "createImage",
      "action": "aws:createImage",
      "onFailure": "Abort",
      "inputs": {
        "InstanceId": "{{ InstanceId }}",
        "ImageName": "VoIP-Weekly-Backup-AMI-{{ 'now' | date('YYYYMMdd-HHmmss') }}",
        "NoReboot": "{{ NoReboot }}"
      }
    }
  ],
  "outputs": [
    "createImage.ImageId"
  ]
}

I have checked the official documents about actions, and it looks like aws:createImage indeed exists, so I wonder what is wrong with my settings or syntax? What am I missing? What can I do to fix this issue? I would really appreciate any help.

Answer 1

Based on the comments.

The solution was to use Schema version 0.3 instead of newer 2.2. It seems that new schema does not support all actions.