Rubyonrails ActiveRecord：：Base：Class 的未定义方法 raise_in_transactional_callbacks=' (NoMethodError)

在写这个问题之前，我看了这些答案，但找不到解决办法

Error when execute rails generate scaffold User name:string email:string

rake aborted! undefined method `migration_error=' for ActiveRecord::Base:Class

Error launching Rails server: undefined method 'configure'

当我try 启动一个新的应用程序(Hartl's tutorial，第2章)时，在scaffold start阶段，我遇到了如下错误:

**undefined method `configure' for #<SampleApp2::Application:0x00000101a74610> (NoMethodError)**

但由于上面的例子，我编辑了development.rb文件:

DemoApp::Application.configure do

(是的，我的申请名为demo_app，所以我改变了它的名字).

之后，我再次try 运行scaffold，但出现了一个新错误:

**method_missing': undefined method raise_in_transactional_callbacks=' for ActiveRecord::Base:Class (NoMethodError)**

针对类似的情况，我们提出了一个migration方法——应该将其从文件开发中删除.rb.类似地，我试图在这个文件raise_in_transactional_callbacks中找到方法，但它不存在！

C:\Sites\demo_app>rails generate scaffold User name:string email:string
invoke  active_record
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activerecord-4.0.2/lib/active_record/dynamic_matchers.rb:22:in `method_missing': undefined method `raise_in_transactional_callbacks=' for ActiveRecord::Base:Class (NoMethodError)
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activerecord-4.0.2/lib/active_record/railtie.rb:166:in `block (3 levels) in <class:Railtie>'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activerecord-4.0.2/lib/active_record/railtie.rb:165:in `each'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activerecord-4.0.2/lib/active_record/railtie.rb:165:in `block (2 levels) in <class:Railtie>'
…
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/railties-4.0.2/lib/rails/commands.rb:48:in `<top (required)>'
from bin/rails:4:in `require'
from bin/rails:4:in `<main>'

在哪里...(省略号)-专门剪切类似代码.