安装aws-sdk后出错

我正在尝试让回形针与 S3 一起使用，但我的视图抛出错误：

cannot load such file -- aws-sdk (You may need to install the aws-sdk gem)

我的 Rails 配置如下：

Gemfile

...
gem "paperclip", "~> 3.0"
gem 'aws-sdk'
...

Model

user.rb

...
has_attached_file :avatar, :styles => { :medium => "300x300>", :thumb => "100x100>" },
                         :storage => :s3,
                         :bucket => ENV['lumeo-dev'],
                         :s3_credentials => "lumeot/config/aws.yml",
                         :path => "/:style/:id/:filename"
...

配置/aws.yml

development:
  bucket: lumeo-dev
  access_key_id: #
  secret_access_key: #
test:
  bucket: lumeo-test
  access_key_id: #
  secret_access_key: #
production:
  bucket: lumeo-pro
  access_key_id: #
  secret_access_key: #

其中“#”表示正确的 id/key

模板：

  <%= simple_form_for(resource, :as => resource_name, :url =>
  registration_path(resource_name), :html => { :method => :put, :multipart => true }) do |f| %>
     <%= f.error_notification %>
            <div class="inputs">
               <p>
                    <% if current_user.avatar.present? %>
                        Change Photo
                        <%= image_tag @user.avatar.url(:thumb) %>
                    <% else %>
                        Upload New Photo 
                        <%= gravatar_for current_user %>
                    <% end %>
               </p>
               <%= f.file_field :avatar %>
....

如果您发现任何可能有帮助的错误信息，请告诉我。谢谢

尝试重新启动您的服务器。我有同样的错误，这对我有用。