Browse button is not working for carrierwave and uplodify

Question

Hi I am uploading the video from my rails app. For this I am using carrierwave gem.

I am referring this tutorial for it.

But when I tried to upload the video from my computer by using Browse button it is not allowing me to browse. When I checked in the firebug I have getting this type of error

"NetworkError: 404 Not Found  - http://localhost:3000/videos/uploadify.swf?preventswfcaching=1393936089114"

I tried to solve it but I didn't get any solution for it.

Here is my videos controller

class VideosController < ApplicationController  

  def index
  end

  def show
    @video = Video.find(params[:id])
  end

  def new
    @video = Video.new(video_params)
  end

  def create
    @video = Video.new(video_params)
    if @video.save
      render :nothing => true
    else
      render :nothing => true, :status => 400
    end
  end

  private
  def video_params
    params.require(:video).permit(:attachment, :zencoder_output_id, :processed, :video, :meta_info) if params[:gallery]
  end 
end

model - video.rb

class Video < ActiveRecord::Base 
  belongs_to :gallery 
  mount_uploader :video, VideoUploader
end

uploader file

class VideoUploader < CarrierWave::Uploader::Base

  include CarrierWave::Video
  storage :file
  def store_dir
    "videos/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
  end

  process encode_video: [:mp4, resolution: "200x200"] 
  def extension_white_list
    %w(avi mov mkv mpg mpeg mp4 m4v flv)
  end    
end

I am using rails 4 and ruby 2.1.0