Why is my cc1.4xlarge instance failing?

Background

Some EC2 instances are failing with an error message that contains the following:

Invalid response HTTP code: 422: Error:InsufficientInstanceCapacity: We are no longer adding cc1.4xlarge capacity and recommend that you utilize cc2.8xlarge instances. cc2.8xlarge instances provide high performance at a low cost and support additional features, including Amazon VPC. 

Answer

EC2 is steering support away from cc1.4xlarge instances and toward cc2.8xlarge instances. The cc2.8xlarge instance supports additional features such as VPC and availability in all regions. When creating instances in the RightScale Dashboard, use cc2.8xlarge instances instead of cc1.4xlarge.