Background worker prevents photos from uploading

I have the carrier wave gem installed and I added a background worker to it (carrierwave_backgrounder gem`). The issue is now when I upload a photo it shows an empty box where the photo should be.

Photos model:

  mount_uploader :image, ImageUploader
  process_in_background :image
  store_in_background :image

image_uploader.rb:

  include CarrierWave::ImageOptimizer
  include CarrierWave::MiniMagick
  include ::CarrierWave::Backgrounder::Delay

/initializers/carrierwave_backgrounder.rb:

CarrierWave::Backgrounder.configure do |c|

  c.backend :sidekiq, queue: :carrierwave
end

Migration:

class AddTempToUser < ActiveRecord::Migration
  def change
    add_column :users, :avatar_tmp, :string
  end

Photos controller:

 def create
    @photo = Photo.create(photo_params)
    @photo.user = current_user
    if @photo.valid? and @photo.save!
      flash[:notice] = "Successfully created photos."
      redirect_to :back
    else
      flash[:notice] = @photo.errors.messages[:base].first
      render :action => 'new'
    end
  end

Server logs:

Jul 31 17:28:07 areyoutaken app/web.1:  Processing by PhotosController#create as JS 
Jul 31 17:28:07 areyoutaken app/web.1:  Processing by PhotosController#create as JS 
Jul 31 17:28:07 areyoutaken app/web.1:    Parameters: {"utf8"=>"✓", "authenticity_token"=>"xhE8IGs/FLF+cJvMWMJeC5sUFkGk76Xe6SoWzT8v1Pg=", "photo"=>{"image"=>#<ActionDispatch::Http::UploadedFile:0x007f7e80662960 @tempfile=#<Tempfile:/tmp/RackMultipart20150801-3-eiq7px>, @original_filename="love.jpg", @content_type="image/jpeg", @headers="Content-Disposition: form-data; name=\"photo[image]\"; filename=\"love.jpg\"\r\nContent-Type: image/jpeg\r\n">}} 
Jul 31 17:28:07 areyoutaken app/web.1:    Parameters: {"utf8"=>"✓", "authenticity_token"=>"xhE8IGs/FLF+cJvMWMJeC5sUFkGk76Xe6SoWzT8v1Pg=", "photo"=>{"image"=>#<ActionDispatch::Http::UploadedFile:0x007f7e80662960 @tempfile=#<Tempfile:/tmp/RackMultipart20150801-3-eiq7px>, @original_filename="love.jpg", @content_type="image/jpeg", @headers="Content-Disposition: form-data; name=\"photo[image]\"; filename=\"love.jpg\"\r\nContent-Type: image/jpeg\r\n">}}