我无法使用rails连接到浏览器。 'rails s'给了我：
/usr/local/lib/ruby/gems/2.3.0/gems/activesupport- 4.0.0/lib/active_support/values/time_zone.rb:282: warning: circular argument reference - now
=> Booting WEBrick
=> Rails 4.0.0 application starting in development on http://0.0.0.0:3000
=> Run `rails server -h` for more startup options
=> Ctrl-C to shutdown server
[2016-03-06 14:06:07] INFO WEBrick 1.3.1
[2016-03-06 14:06:07] INFO ruby 2.3.0 (2015-12-25) [x86_64-darwin15]
[2016-03-06 14:06:07] INFO WEBrick::HTTPServer#start: pid=4336 port=3000
将“localhost：3000”放入浏览器时，我收到以下错误消息：
ActiveRecord::ConnectionNotEstablished
Rails.root: /Users/annetteroberts/Sites/simple_cms
看起来像一个简单的问题！
这是我的日志吐出来的
tarted GET "/" for 127.0.0.1 at 2016-03-07 21:05:50 +0000
ActiveRecord::ConnectionNotEstablished (ActiveRecord::ConnectionNotEstablished):
activerecord (4.0.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:546:in `retrieve_connection'
activerecord (4.0.0) lib/active_record/connection_handling.rb:79:in `retrieve_connection'
activerecord (4.0.0) lib/active_record/connection_handling.rb:53:in `connection'
activerecord (4.0.0) lib/active_record/query_cache.rb:51:in `restore_query_cache_settings'
activerecord (4.0.0) lib/active_record/query_cache.rb:43:in `rescue in call'
activerecord (4.0.0) lib/active_record/query_cache.rb:32:in `call'
activerecord (4.0.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:626:in `call'
activerecord (4.0.0) lib/active_record/migration.rb:369:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.0.0) lib/active_support/callbacks.rb:373:in `_run__922298227330934617__call__callbacks'
activesupport (4.0.0) lib/active_support/callbacks.rb:80:in `run_callbacks'
actionpack (4.0.0) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/reloader.rb:64:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/remote_ip.rb:76:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
railties (4.0.0) lib/rails/rack/logger.rb:38:in `call_app'
railties (4.0.0) lib/rails/rack/logger.rb:21:in `block in call'
activesupport (4.0.0) lib/active_support/tagged_logging.rb:67:in `block in tagged'
activesupport (4.0.0) lib/active_support/tagged_logging.rb:25:in `tagged'
activesupport (4.0.0) lib/active_support/tagged_logging.rb:67:in `tagged'
railties (4.0.0) lib/rails/rack/logger.rb:21:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/request_id.rb:21:in `call'
rack (1.5.5) lib/rack/methodoverride.rb:21:in `call'
rack (1.5.5) lib/rack/runtime.rb:17:in `call'
activesupport (4.0.0) lib/active_support/cache/strategy/local_cache.rb:83:in `call'
rack (1.5.5) lib/rack/lock.rb:17:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/static.rb:64:in `call'
railties (4.0.0) lib/rails/engine.rb:511:in `call'
railties (4.0.0) lib/rails/application.rb:97:in `call'
rack (1.5.5) lib/rack/lock.rb:17:in `call'
rack (1.5.5) lib/rack/content_length.rb:14:in `call'
rack (1.5.5) lib/rack/handler/webrick.rb:60:in `service'
/usr/local/Cellar/ruby/2.3.0/lib/ruby/2.3.0/webrick/httpserver.rb:140:in `service'
/usr/local/Cellar/ruby/2.3.0/lib/ruby/2.3.0/webrick/httpserver.rb:96:in `run'
/usr/local/Cellar/ruby/2.3.0/lib/ruby/2.3.0/webrick/server.rb:296:in `block in start_thread'
Rendered /usr/local/lib/ruby/gems/2.3.0/gems/actionpack-4.0.0/lib/action_dispatch/middleware/templates/rescues/_source.erb (1.0ms)
Rendered /usr/local/lib/ruby/gems/2.3.0/gems/actionpack-4.0.0/lib/action_dispatch/middleware/templates/rescues/_trace.erb (2.5ms)
Rendered /usr/local/lib/ruby/gems/2.3.0/gems/actionpack-4.0.0/lib/action_dispatch/middleware/templates/rescues/_request_and_response.erb (2.4ms)
Rendered /usr/local/lib/ruby/gems/2.3.0/gems/actionpack-4.0.0/lib/action_dispatch/middleware/templates/rescues/diagnostics.erb within rescues/layout (63.7m