以下是运行rake以加载生产数据库模式（mysql 5.1.45）的错误：
$ rake db:schema:load RAILS_ENV=production --trace
** Invoke db:schema:load (first_time)
** Invoke environment (first_time)
** Execute environment
rake aborted!
No such middleware to insert before: ActionDispatch::Static
c:/Ruby192/lib/ruby/gems/1.9.1/gems/actionpack-3.1.0/lib/action_dispatch/middleware/stack.rb:119:in `assert_index'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/actionpack-3.1.0/lib/action_dispatch/middleware/stack.rb:83:in `insert'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/configuration.rb:38:in `block in merge_into'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/configuration.rb:37:in `each'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/configuration.rb:37:in `merge_into'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/engine.rb:445:in `app'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/application/finisher.rb:37:in `block in <module:Finisher>'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/initializable.rb:25:in `instance_exec'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/initializable.rb:25:in `run'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/initializable.rb:50:in `block in run_initializers'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/initializable.rb:49:in `each'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/initializable.rb:49:in `run_initializers'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/application.rb:92:in `initialize!'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/railtie/configurable.rb:30:in `method_missing'
D:/rails_proj/emclab-failed/config/environment.rb:5:in `<top (required)>'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/application.rb:78:in `require'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/application.rb:78:in `require_environment!'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/railties-3.1.0/lib/rails/application.rb:189:in `block (2 levels) in initialize_tasks'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:205:in `call'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:205:in `block in execute'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:200:in `each'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:200:in `execute'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:158:in `block in invoke_with_call_chain'
c:/Ruby192/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:151:in `invoke_with_call_chain'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:176:in `block in invoke_prerequisites'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:174:in `each'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:174:in `invoke_prerequisites'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:157:in `block in invoke_with_call_chain'
c:/Ruby192/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:151:in `invoke_with_call_chain'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/task.rb:144:in `invoke'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:112:in `invoke_task'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:90:in `block (2 levels) in top_level'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:90:in `each'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:90:in `block in top_level'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:129:in `standard_exception_handling'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:84:in `top_level'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:62:in `block in run'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:129:in `standard_exception_handling'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/application.rb:59:in `run'
c:/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/bin/rake:32:in `<top (required)>'
c:/Ruby192/bin/rake:19:in `load'
c:/Ruby192/bin/rake:19:in `<main>'
Tasks: TOP => db:schema:load => environment
请忽略以下内容：stackoverflow需要比错误消息更多的单词来解释这种情况。错误信息比任何单词都好！
有任何解决问题的建议吗？感谢。
答案 0 :(得分：1)
您不必指定另一块中间件插入中间件堆栈的前端。相反，您只能指定索引号。例如：
config.middleware.insert_before(0, ::API::Throttle)
答案 1 :(得分：0)
根据someone who had a similar problem，您可能需要进入config/application.rb并替换：
config.middleware.insert_after('ActionDispatch::Static', '::API::Throttle')
改为使用此行：
config.middleware.insert_before('Rack::Lock', '::API::Throttle')
希望这有帮助！