@Christian_Dahlqvist, here's the response. I found the same error occurs when deleting the index from Kibana -> Management-> Index Management
{ "cluster_name" : "elasticsearch", "status" : "yellow", "timed_out" : false, "number_of_nodes" : 1, "number_of_data_nodes" : 1, "active_primary_shards" : 21, "active_shards" : 21, "relocating_shards" : 0, "initializing_shards" : 0, "unassigned_shards" : 13, "delayed_unassigned_shards" : 0, "number_of_pending_tasks" : 1, "number_of_in_flight_fetch" : 0, "task_max_waiting_in_queue_millis" : 0, "active_shards_percent_as_number" : 61.76470588235294 }
And I found below warrning: does it matter?
`
log [08:44:58.841] [warning][reporting] Generating a random key for xpack.reporting.encryptionKey. To prevent pending reports from failing on restart, please set xpack.reporting.encryptionKey in kibana.yml
`