title: Elastic Beanstalk Invalid Parameter Value
body: <p>I was getting a fairly ambiguous error from my app.config elastic beanstalk configuration file.  </p>
  
  <p>app.config</p>
  
  <pre><code>option_settings:
     - namespace: aws:elasticbeanstalk:application:environment
       option_name: NODE_ENV
       value: production
     - namespace: aws:elasticbeanstalk:container:nodejs:staticfiles
       option_name: /public
       value: /public
     - namespace: aws:elasticbeanstalk:container:nodejs
       option_name: NodeVersion
       value: 0.10.26
  packages: 
    yum:
      GraphicsMagick: []
  files:
      "/etc/nginx/conf.d/proxy.conf" :
          mode: "000755"
          owner: root
          group: root
          content: |
             client_max_body_size 10M;
  </code></pre>
  
  <p>command line</p>
  
  <pre><code>&gt; eb create --cfg med-env-sc
  ...
  Printing Status:
  INFO: createEnvironment is starting.
  INFO: Using elasticbeanstalk-us-east-1-466215906046 as Amazon S3 storage bucket for environment data.
  ERROR: InvalidParameterValue: Parameter values must be a string or a list of strings
  ERROR: Failed to launch environment.
  ERROR: Failed to launch environment.
  </code></pre>