Multiple file upload to s3

Hi,
I am struck at following error for uploading multiple files to s3. I am
Using paperclip and aws-sdk for upload and rails 3.2.13 and ruby 1.9
Paperclip::AdapterRegistry::NoHandlerError in #create

as for multiple file upload in form am using

<%= form_for (@model, :html => {:multipart => true }) do |f| %>

<%= f.file_field :attach, multiple: true, :name => ‘candidate[attach]’
%>

anyway single file is uploaded successfully to s3.