我正在开发中将应用程序从Rails 4.2升级到Rails 5 beta1.1.应用程序升级前运行良好.我已经完成了基本的升级步骤(更新
Ruby,更新Rails以及相关步骤：
http://edgeguides.rubyonrails.org/upgrading_ruby_on_rails.html). Gemfile也已更新到最新的Gems.
当我运行$rails中间件或$rails控制台或$rails服务器时,我收到以下错误：
No such middleware to insert after: ActionDispatch::ParamsParser .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/actionpack/lib/action_dispatch/middleware/stack.rb:108:in `assert_index' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/actionpack/lib/action_dispatch/middleware/stack.rb:80:in `insert_after' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/configuration.rb:69:in `block in merge_into' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/configuration.rb:68:in `each' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/configuration.rb:68:in `merge_into' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/engine.rb:507:in `block in app' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/engine.rb:504:in `synchronize' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/engine.rb:504:in `app' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/application/finisher.rb:34:in `block in <module:Finisher>' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/initializable.rb:30:in `instance_exec' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/initializable.rb:30:in `run' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/initializable.rb:55:in `block in run_initializers' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/initializable.rb:54:in `run_initializers' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/application.rb:350:in `initialize!' .../config/environment.rb:5:in `<top (required)>' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/activesupport/lib/active_support/dependencies.rb:302:in `require' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/activesupport/lib/active_support/dependencies.rb:302:in `block in require' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/activesupport/lib/active_support/dependencies.rb:268:in `load_dependency' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/activesupport/lib/active_support/dependencies.rb:302:in `require' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/application.rb:326:in `require_environment!' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/application.rb:446:in `block in run_tasks_blocks' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/commands/rake_proxy.rb:13:in `block in run_rake_task' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/commands/rake_proxy.rb:10:in `run_rake_task' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/commands/commands_tasks.rb:51:in `run_command!' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/command.rb:20:in `run' .../.rvm/gems/ruby-2.3.0/bundler/gems/rails-dbf67b3a6f54/railties/lib/rails/commands.rb:19:in `<top (required)>' bin/rails:4:in `require' bin/rails:4:in `<main>'
这与ActionDispatch :: ParamsParser已从Rails 5 beta中间件(https://github.com/rails/rails/commit/38d2bf5fd1f3e014f2397898d371c339baa627b1)中删除的事实有关.但是,在某种程度上我的应用程序似乎仍然在寻找它.
我在config / application.rb中尝试过各种各样的ActionDispatch :: ParamsParser,比如删除它,当它不起作用时,我也尝试添加它.同样的错误.有没有办法克服这个错误？
解决方法
我相信这个错误是由一个尚未更新Rails 5的gem引起的.我一直在使用gem remotipart(
https://github.com/JangoSteve/remotipart).这非常有帮助.当我从gem文件中删除它时,问题中提到的错误消失了.