Snapshot restore error "unsupported snapshot state"

Elastic Stack Elasticsearch
1

Hi.
I want to migrate 1TB of data to a new cluster but the snapshot/restore takes forever so I wanted to migrate just one index for testing purposes:
curl -XPUT 'localhost:9200/_snapshot/my_backup/snapshot_3?pretty' -d'
{ "indices": "logstash-2012.11.01", "ignore_unavailable": true, "include_global_state": false}'

and want to restore it on another cluster but am getting
{"error":"SnapshotRestoreException[[my_backup:snapshot_3] unsupported snapshot state [FAILED]]","status":500}

what am I doing wrong?