plugin not recognizable with elasticsearch 5.6.4

[shivarammysore]

# curl -X GET 'http://localhost:9200'
{
  "name" : "WAVImbK",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "f70CqONkSmum0djcddQjRg",
  "version" : {
    "number" : "5.6.4",
    "build_hash" : "8bbedf5",
    "build_date" : "2017-10-31T18:55:38.105Z",
    "build_snapshot" : false,
    "lucene_version" : "6.6.1"
  },
  "tagline" : "You Know, for Search"

# /usr/share/elasticsearch/bin/elasticsearch-plugin install lmenezes/elasticsearch-kopf/v2.1.2
ERROR: Unknown plugin lmenezes/elasticsearch-kopf/v2.1.2

[drummerwolli]

see https://github.com/lmenezes/elasticsearch-kopf/issues/390 and the respective answers