Rancher Restore KO

Hi All,
I’m using Rancher 2.1.6 and I’m encountering an error during restore.
I’m following the manual integrated in this link :

https://rancher.com/docs/rancher/v2.x/en/backups/restorations/ha-restoration/

I obtain the error during the execution of this command : (chapter 4-Restore Database)

**rke etcd snapshot-restore --name .db --config ./rancher-cluster-restore.ym**l

follows you can find the description error:

INFO[0000] Restoring etcd snapshot etcd.20190327.db
INFO[0000] Successfully Deployed state file at [./rancher-cluster-restore.rkestate]
INFO[0000] [dialer] Setup tunnel for host [10.0.2.237]
WARN[0005] failed to stop etcd container on host [10.0.2.237]: Can’t stop Docker container [etcd] for host [10.0.2.237]: Error response from daemon: No such container: etcd
INFO[0005] [etcd] starting backup server on host [10.0.2.237]
INFO[0006] [etcd] Successfully started [etcd-Serve-backup] container on host [10.0.2.237]
WARN[0011] failed to start backup server on host [10.0.2.237]: Failed to run backup server container, container logs: time=“2019-03-28T13:36:03Z” level=fatal msg=“open /etc/kubernetes/ssl/kube-ca.pem: no such file or directory”

WARN[0011] failed to start etcd container on host [10.0.2.237]: Failed to start [etcd] container on host [10.0.2.237]: Error response from daemon: No such container: etcd
FATA[0011] failed to start backup server on all etcd nodes: [Failed to run backup server container, container logs: time=“2019-03-28T13:36:03Z” level=fatal msg=“open /etc/kubernetes/ssl/kube-ca.pem: no such file or directory”
]

Is there someone who can help me?

thanks in advance
Manuel