Cluster is down: new node can't join cluster

Failed to reconcile etcd plane: Failed to add etcd member [etcd-ip-xxx] to etcd cluster:

I’m new to Rancher. One of our Rancher nodes was unresponsive. I attempted to ‘stop’ the node in AWS. AWS terminated the instance and started up a new instance in it’s place, with a new IP.

Rancher then attempted to register the node and it was hung in a ‘Registering’ state. The instance terminated by AWS was in an ‘Unavailable’ state.

As a result, the cluster is unavailable.

How do I fix this? Can I delete the reference to the ‘Unavailable’ node? Will this free up the processes on Rancher?