title: Service Role ARN blank in CodeDeploy
body: <p>I am trying to setup the CodeDeploy service with one of my ec2 instances. On the form to do this, everything works properly until I reach the "Service Role" section. </p>
  
  <p>This field does not display any possible ARNs.</p>
  
  <p>This is what I see:</p>
  
  <p><img src="https://i.imgur.com/N8VmeCb.png?1" alt="img"></p>
  
  <p>I created an IAM user and gave them Admin privileges and pasted their ARN into this field and got the error message</p>
  
  <blockquote>
    <p>Cannot assume role provided.</p>
  </blockquote>
  
  <p>Does anyone know the reason this is happening?</p>