Issue while installing plugin

Hi Team,

I am trying to use groovy in kibana. i am trying to install plugins (mapper-attachements and lang-groovy).i used the below command
bin/plugin install mapper-attachments
but i got error stating
ERROR: failed to download out of all possible locations..., use --verbose to get
detailed information.

Please correct me. where did i go wrong ?

Either you are behind a proxy or you are using elasticsearch < 2.0.

My 2 cents

Thank you David !!