Unsupported driver '' : Empty driver when driver is set to otto for Javascript

Hello,
I am new to tyk so for a quick start up, I have cloned the github project and configured the existing test api proxy with the following configs

{
    "name": "Tyk Test Keyless API",
    "org_id": "default",
    "definition": {
        "location": "header",
        "key": "version"
    },
    "use_keyless": true,
    "version_data": {
        "not_versioned": true,
        "versions": {
            "Default": {
                "name": "Default"
            }
        }
    },
    "custom_middleware": {
        "pre": [
            {
                "name": "testJSVMData",
                "path": "./middleware/injectHeader.js",
                "require_session": false,
                "raw_body_only": false,
            }
        ]
    },
    "driver": "otto",
    "proxy": {
        "listen_path": "/my-keyless-test/",
        "target_url": "http://httpbin.org",
        "strip_listen_path": true
    }
}

the proxy works well but I got the following error log with an empty driver

tyk-gateway_1  | time="Apr 11 10:20:12" level=error msg="Unsupported driver ''" prefix=coprocess

TYK 5.1.0 config in docker

{
  "log_level": "debug",
  "listen_port": 8080,
  "secret": "352d20ee67be67f6340b4c0605b044b7",
  "template_path": "/opt/tyk-gateway/templates",
  "tyk_js_path": "/opt/tyk-gateway/js/tyk.js",
  "middleware_path": "/opt/tyk-gateway/middleware",
  "use_db_app_configs": false,
  "app_path": "/opt/tyk-gateway/apps/",
  "storage": {
    "type": "redis",
    "host": "tyk-redis",
    "port": 6379,
    "username": "",
    "password": "",
    "database": 0,
    "optimisation_max_idle": 2000,
    "optimisation_max_active": 4000
  },
  "enable_analytics": false,
  "analytics_config": {
    "type": "",
    "ignored_ips": []
  },
  "health_check": {
    "enable_health_checks": false,
    "health_check_value_timeouts": 60
  },
  "enable_non_transactional_rate_limiter": true,
  "enable_sentinel_rate_limiter": false,
  "enable_redis_rolling_limiter": false,
  "allow_master_keys": false,
  "policies": {
    "policy_source": "file",
    "policy_path": "/opt/tyk-gateway/policies"
  },
  "hash_keys": true,
  "close_connections": false,
  "http_server_options": {
    "enable_websockets": true
  },
  "allow_insecure_configs": true,
  "coprocess_options": {
    "enable_coprocess": true,
    "coprocess_grpc_server": ""
  },
  "enable_bundle_downloader": true,
  "bundle_base_url": "",
  "global_session_lifetime": 100,
  "force_global_session_lifetime": false,
  "max_idle_connections_per_host": 500,
  "enable_jsvm": true
}

Any help will be appreciated thank you !

I believe you simply missing the plugin driver name. Previously this would default to Javascript (Otto) when empty. But nowadays, driver names have to be explicitly specified.