下载图片报错

config/routes.rb

@@ -4,6 +4,8 @@ Rails.application.routes.draw do
   require 'admin_constraint'
   mount Sidekiq::Web => '/sidekiq', :constraints => AdminConstraint.new
 
+  get 'attachments/download/:id', to: 'attachments#show'
+
   resources :edu_settings
   scope '/api' do
     get 'home/index'