title: You may not specify a referenced group id for an existing IPv4 CIDR rule. prompt when editing the Inbound rule in AWS Security Group
body: <p>In AWS EC2,  I start a Classical Load Balancer in front of EC2 instance (security group of EC2 instance is <strong>launch-wizard-3</strong>).  i want to change the inbound rule of Security Group of EC2 instance . A security group for Classical Load Balancer (it's name is <strong>my-first-load-balancer-sg</strong>) was also started. when i am changing source of an inbound rule of <strong>launch-wizard-3</strong> to the <strong>my-first-load-balancer-sg</strong>, following error is prompted. I tried many times to solve it, but i couldn't.</p>
  <p>the error- You may not specify a referenced group id for an existing IPv4 CIDR rule.</p>
  <p>the inbound rule as follows</p>
  <p>(type-HTTP, protocol-TCP, port rang-80, Source type- Custom, Source- <strong>my-first-load-balancer-sg</strong>(what i want to place) )</p>
  <p>Please help me~! Thanks!</p>