Paperclip validation issue on production

I have a Problem when I deploy my application on google cloud I get this error

has contents that are not what they are reported to be

Locally it works fine! I already tried to using the command_path. So I really don't know what I have to do next...

This is my model

has_mongoid_attached_file  :image,
    :styles => { :large => "380x380!" , :medium => "240x240", :small => "120x120!" },
    :storage => :fog,
    :fog_public => true,
    :fog_directory => 'XXXX',
    :path => "images/:id/:style/:basename.:extension",
    :fog_credentials => {  :provider => 'Google',
                           :google_storage_access_key_id => 'XXXXX',
                           :google_storage_secret_access_key => 'XXXXX'}

  validates_attachment_content_type :image, :content_type => ["image/jpg", "image/jpeg", "image/png", "image/gif"]

Thank you for your efforts. I hope you guys can help me

Okay I found a result. I just created a initializers/paperclip.rb file

require 'paperclip/media_type_spoof_detector'
module Paperclip
  class MediaTypeSpoofDetector
    def spoofed?
      false
    end
  end
end

Right now it work's perfectly for me.

If you have problems with ImageMagick on App Engine using Rails see this link