Paperclip size validation error message displayed twice

Question

In redemption_image.rb,

class RedemptionImage < ActiveRecord::Base
  belongs_to :business, :touch => true

  has_attached_file :display_image, :url => "/system/:class/:attachment/:id_partition/:hash.:extension",
                               :hash_secret => "redemptionimagesqqqa"
  validates_attachment :display_image, :content_type => { :content_type => /\Aimage/ }, :size => { :in => 0..300.kilobytes,
:message => "must be lesser than 300 KB. Image height and width must be lesser than 500 px." }

there is a validation for size, content_type and presence for display_image. It displays the message twice: Error saving redemption image: Display image file size must be lesser than 300 KB. Image height and width must be lesser than 500 px.,Display image must be lesser than 300 KB. Image height and width must be lesser than 500 px.

If no customized message is provided, then it flashes error twice as shown in figure