Paul, It is possible to repair the instance by mounting it's EBS volume on another instance and copying the key files from another working instance in the cluster (since they all accept the same key). You would need to do this manually, however - It's not something Cloudera Live can do. It has no direct access to your account. It works by SSH credentials set up by the instances, and then deletes these keys when it's finished. There are several blog and forum posts detailing how to do this, e.g. http://automagical.rationalmind.net/2015/09/28/regain-access-aws-ec2-instance-lost-access/. It is a tricky procedure. If you don't have valuable data on this cluster, you may also consider deleting your cluster, registering for a new access code and starting a new cluster.
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