设置rails应用程序的问题。它第一次工作，但后来当我重新打开它，并试图运行'rails服务器'它不工作，并返回以下错误。谢谢。
我正在使用Ruby 2.3.1p112 Rails 5.0 MySQL 5.7.13 $ Rails服务器
=> Boot Puma
=> Rails 5.0.0应用程序在http：//localhost：3000上开始开发
=>运行rails server -h获取更多启动选项正在退出
/Users/布鲁斯/sea/config/routes.rb：6：in `<top（required）'：undefined
main：Object的方法“root”（NoMethodError）

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/activesupport-

字符串
5.0.0/lib/active_support/dependencies.rb：287：in `load'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/activesupport-

型
5.0.0/lib/active_support/dependencies.rb：287：in `block in load'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/activesupport-

型
5.0.0/lib/active_support/dependencies.rb：259：in `load_dependencies '

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/activesupport-

型
5.0.0/lib/active_support/dependencies.rb：287：in `load'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

型
/rails/application/routes_reloader.rb：40：in `block in load_paths'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

型
/rails/application/routes_reloader.rb：40：in `each'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

型
/rails/application/routes_reloader.rb：40：in `load_paths'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

型
/rails/application/routes_reloader.rb：16：in `reload！'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

型
/rails/application/routes_reloader.rb：26：in `block in updater'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/activesupport-

型
5.0.0/lib/active_support/file_update_checker.rb：77：in `execute'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

型
/rails/application/routes_reloader.rb：27：in `updater'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

型
/rails/application/routes_reloader.rb：7：in `execute_if_updated'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

型
/rails/application/finisher.rb：119：in `block in module：Finisher'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

型
/rails/initializable.rb：30：在`instance_exec'中

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

型
/rails/initializable.rb：30：in 'run'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

型
/rails/initializable.rb：55：in `block in run_initializers'

from /Users/bruce/.rvm/rubies/ruby-2.3.1/lib/ruby/2.3.0

型
/tsort.rb：228：in `block in tsort_each'

from /Users/bruce/.rvm/rubies/ruby-2.3.1/lib/ruby/2.3.0

型
/tsort.rb：350：in `block（2 levels）in each_strongly_connected_component'

from /Users/bruce/.rvm/rubies/ruby-2.3.1/lib/ruby/2.3.0

型
/tsort.rb：431：在`each_strongly_connected_component_from'中

from /Users/bruce/.rvm/rubies/ruby-2.3.1/lib/ruby/2.3.0

型
/tsort.rb：349：in `block in each_strongly_connected_component'

from /Users/bruce/.rvm/rubies/ruby-2.3.1/lib/ruby/2.3.0

型
/tsort.rb：347：在`each'中

from /Users/bruce/.rvm/rubies/ruby-2.3.1/lib/ruby/2.3.0

/tsort.rb：347：in `call'

from /Users/bruce/.rvm/rubies/ruby-2.3.1/lib/ruby/2.3.0

/tsort.rb：347：在`each_strong_connected_component'中

from /Users/bruce/.rvm/rubies/ruby-2.3.1/lib/ruby/2.3.0

/tsort.rb：226：在`tsort_each'中

from /Users/bruce/.rvm/rubies/ruby-2.3.1/lib/ruby/2.3.0

/tsort.rb：205：在`tsort_each'中

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

/rails/initializable.rb：54：in `run_initializers'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

型
/rails/application.rb：352：in `initialize！'

from /Users/bruce/sea/config/environment.rb:5:in `<top (required)>'

from /Users/bruce/sea/config.ru:3:in `require_relative'

from /Users/bruce/sea/config.ru:3:in `block in <main>'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/rack-2.0.1/lib

型
/rack/builder.rb：55：在`instance_eval'中

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/rack-2.0.1/lib

型
/rack/builder.rb：55：in `initialize'

from /Users/bruce/sea/config.ru:in `new'

from /Users/bruce/sea/config.ru:in `<main>'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/rack-2.0.1/lib

型
/rack/builder.rb：49：在`eval'中

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/rack-2.0.1/lib

型
/rack/builder.rb：49：in `new_from_string'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/rack-2.0.1/lib

型
/rack/builder.rb：40：在`parse_file'中

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/rack-2.0.1/lib

/rack/server.rb：318：在`build_app_and_options_from_config'中

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/rack-2.0.1/lib

/rack/server.rb：218：in `app'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

/rails/commands/server.rb：59：in `app'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/rack-2.0.1/lib

/rack/server.rb：353：在`wrapped_app'中

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

/rails/commands/server.rb：124：in `log_to_stdout'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

/rails/commands/server.rb：77：in `start'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

/rails/commands/commands_tasks.rb：90：in `block in server'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

/rails/commands/commands_tasks.rb：85：in `tap'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

/rails/commands/commands_tasks.rb：85：in `server'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

/rails/commands/commands_tasks.rb：49：in `run_command！'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/railties-5.0.0/lib

/rails/commands.rb：18：in `<top（required）>'

from /Users/bruce/sea/bin/rails:9:in `require'

from /Users/bruce/sea/bin/rails:9:in `<top (required)>'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/spring-1.7.2/lib

/spring/client/rails.rb：28：in `load'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/spring-1.7.2/lib

/spring/client/rails.rb：28：in `call'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/spring-1.7.2/lib

/spring/client/command.rb：7：in `call'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/spring-1.7.2/lib

/spring/client.rb：30：in `run'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/spring-1.7.2/bin

/spring：49：in `<top（required）>'

from /Users/bruce/.rvm/gems/ruby-2.3.1@global/gems/spring-1.7.2/lib

/spring/binstub.rb：11：in load' 来自/Users/布鲁斯/.rvm/gems/ruby-2.3.1@global/gems/spring-1.7.2/lib /spring/binstub.rb：11：in<top（required）>'

from /Users/bruce/sea/bin/spring:13:in `require'

from /Users/bruce/sea/bin/spring:13:in `<top (required)>'

from bin/rails:3:in `load'`enter 

from bin/rails:3:in `<main>'