title: The VPC vpx-xxxxxxxx associated with the default subnet group does not exist
body: <p>Modifying an existing Elastic Beanstalk installation I was trying to create a Postgres database using RDS and got the error message:</p>
  
  <p>"The VPC vpx-xxxxxxxx  associated with the default subnet group does not exist. 
  Please delete the default subnet group or specify another subnet group."</p>
  
  <p>I had looked in AWS, VPC, Your VPCs and had not found vpc-xxxxxxxx.
  I thought the error message was referring to a deleted/hidden setting.</p>