My config.yml throws a 'Contract violation for return value' error

aws:
  # Credentials can be hardcoded or set in environment variables
  access_key_id: XXX
  secret_access_key: XXX
  s3:
    region: ap-southeast-1
    buckets:
        assets: s3://snowplow-hosted-assets #
        jsonpath_assets: #
        log: s3n://XXX-snwplw-etl/logs/ #
        raw:
            in:
            - s3n://XXX-snwplw-logs/ #
            processing: s3n://XXX-snwplw-etl/processing/ #
            archive: s3://XXX-snwplw-archive/raw #
        enriched:
            good: s3://XXX-snwplw-data/enriched/good #
            bad: s3://XXX-snwplw-data/enriched/bad #
            errors: s3://XXX-snwplw-data/enriched/errors #
            archive: s3://XXX-snwplw-data/enriched/archive #
        shredded:
            good: s3://XXX-snwplw-data/shredded/good #
            bad: s3://XXX-snwplw-data/shredded/bad #
            archive: s3://XXX-snwplw-data/shredded/archive #
            errors: s3://XXX-snwplw-data/shredded/errors #
emr:
    ami_version: 4.5.0
    region: ap-southeast-1        # Always set this
    jobflow_role: EMR_EC2_DefaultRole # Created using $ aws emr create-default-roles
    service_role: EMR_DefaultRole     # Created using $ aws emr create-default-roles
    placement: ap-southeast-1a  # Set this if not running in VPC. Leave blank otherwise
    ec2_subnet_id: #subnet-XXX # Set this if running in VPC. Leave blank otherwise
    ec2_key_name: XXX-production
    bootstrap: []           # Set this to specify custom boostrap actions. Leave empty otherwise
    software:
      hbase:                # Optional. To launch on cluster, provide version, "0.92.0", keep quotes. Leave empty otherwise.
      lingual:              # Optional. To launch on cluster, provide version, "1.1", keep quotes. Leave empty otherwise.
    # Adjust your Hadoop cluster below
    jobflow:
      master_instance_type: m1.medium
      core_instance_count: 2
      core_instance_type: m1.medium
      task_instance_count: 0 # Increase to use spot instances
      task_instance_type: m1.medium
      task_instance_bid: 0.015 # In USD. Adjust bid, or leave blank for non-spot-priced (i.e. on-demand) task instances
    bootstrap_failure_tries: 3 # Number of times to attempt the job in the event of bootstrap failures
    additional_info:        # Optional JSON string for selecting additional features
collectors:
  format: cloudfront # For example: 'clj-tomcat' for the Clojure Collector, 'thrift' for Thrift records, 'tsv/com.amazon.aws.cloudfront/wd_access_log' for Cloudfront access logs or 'ndjson/urbanairship.connect/v1' for UrbanAirship Connect events
enrich:
  job_name: Snowplow ETL # Give your job a name
  versions:
    hadoop_enrich: 1.7.0 # Version of the Hadoop Enrichment process
    hadoop_shred: 0.9.0 # Version of the Hadoop Shredding process
    hadoop_elasticsearch: 0.1.0 # Version of the Hadoop to Elasticsearch copying process
  continue_on_unexpected_error: false # Set to 'true' (and set :out_errors: above) if you don't want any exceptions thrown from ETL
  output_compression: NONE # Compression only supported with Redshift, set to NONE if you have Postgres targets. Allowed formats: NONE, GZIP
storage:
  download:
    folder: /home/ec2-user/snowplow-data-download # Postgres-only config option. Where to store the downloaded files. Leave blank for Redshift
  targets:
    - name: "My PostgreSQL database"
      type: postgres
      host: XXX # Hostname of database server
      database: snowplow # Name of database
      port: 5432 # Default Postgres port
      ssl_mode: disable # One of disable (default), require, verify-ca or verify-full
      table: atomic.events
      username: XXX
      password: XXX
      es_nodes_wan_only:
      maxerror: # Not required for Postgres
      comprows: # Not required for Postgres
monitoring:
  tags: {} # Name-value pairs describing this job
  logging:
    level: DEBUG # You can optionally switch to INFO for production
  snowplow:

I am using this version of the runner http://dl.bintray.com/snowplow/snowplow-generic/snowplow_emr_r77_great_auk.zip
and the command to execute is ‘./snowplow-emr-etl-runner --debug --config config.yml --resolver resolver.json’

Looks like it was just indentation issue. Configuration is fine but now I am getting this error when creating the EMR clusters.

‘The requested instance profile EMR_EC2_DefaultRole is invalid’. Anyone faced this before ?

Do both of these roles exist in IAM? You can check that EMR_DefaultRole and EMR_EC2_DefaultRole should both be listed here, or if using the AWS CLI you can run aws iam list-roles to list all IAM roles.