Template format error: Unrecognized resource types

template.yaml

Parameters:
  CreateResource:
    Default: false
    Type: String
    AllowedValues: [true, false]
Conditions:
  ShouldCreateResource:
    !Equals [true, !Ref CreateResource]
Resources:
  Macro:
    Type: AWS::CloudFormation::Macro
    Properties:
      FunctionName: !Ref Function
      Name: macro
  Function:
    Type: AWS::Lambda::Function
    Properties:
      Runtime: python3.7
      Role: !GetAtt Role.Arn
      Code:
        ZipFile: |
          def lambda_handler(event, context):
            if event['params']['CreateResource'] == 'false':
              return {'fragment': {'Type': 'AWS::CloudFormation::WaitConditionHandle'},
                      'requestId': event['requestId'],
                      'status': 'success'}
            else:
              return {'fragment': event['fragment'],
                      'requestId': event['requestId'],
                      'status': 'success'}
      Handler: index.lambda_handler
  Role:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Action: sts:AssumeRole
            Principal:
              Service: lambda.amazonaws.com
  Stack:
    Fn::Transform:                          # add these lines in another commit after the macro
      Name: macro                           # add these lines in another commit after the macro
      Parameters:                           # add these lines in another commit after the macro
        CreateResource: !Ref CreateResource # add these lines in another commit after the macro
    Type: AWS::AppStream::Stack
    Condition: ShouldCreateResource

validate-template / get-template-summary / create-stack-set and create-stack / update-stack through the console throw:
Template format error: Unrecognized resource types: []

create-change-set --change-set-type IMPORT has similar console issues

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https://code.amazon.com/packages/AWS21StackBuilderService/blobs/74ba401db270b8329b602a3218f0bb608a2e74f7/--/src/amzn/aws21/sbs/utils/ResourceTypeValidator.java#L22

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Should not throw this error where we cannot evaluate conditions

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Current workaround of adding transforms like Transform: AWS::Serverless-2016-10-31 to templates:

Transform: AWS::Serverless-2016-10-31 # https://i.amazon.com/CFN-7763

https://stackoverflow.com/q/48228751/cloudformation-conditional-template-validation/69591806#69591806