Cannot generate migrations on rails 2.3.4

I used to work with rails 2.3.2 before and then I decided to upgrade to version 2.3.4.

Today I tried to generate a migration(I could do this fine with version 2.3.2) and I got the following error message:

C:/Program Files (x86)/NetBeans 6.8/ruby2/jruby-1.4.0/lib/ruby/gems/1.8/gems/rails-2.3.4/lib/initializer.rb:812:in `const_missing': uninitialized constant ActiveSupport (NameError)
        from D:/Proyectos/Cursometro/www/config/environment.rb:33
        from C:/Program Files (x86)/NetBeans 6.8/ruby2/jruby-1.4.0/lib/ruby/gems/1.8/gems/rails-2.3.4/lib/initializer.rb:111:in `run'
        from D:/Proyectos/Cursometro/www/config/environment.rb:15
        from D:/Proyectos/Cursometro/www/config/environment.rb:31:in `require'
        from C:/Program Files (x86)/NetBeans 6.8/ruby2/jruby-1.4.0/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
        from C:/Program Files (x86)/NetBeans 6.8/ruby2/jruby-1.4.0/lib/ruby/gems/1.8/gems/rails-2.3.4/lib/commands/generate.rb:1
        from C:/Program Files (x86)/NetBeans 6.8/ruby2/jruby-1.4.0/lib/ruby/gems/1.8/开发者_JAVA百科gems/rails-2.3.4/lib/commands/generate.rb:31:in `require'
        from C:/Program Files (x86)/NetBeans 6.8/ruby2/jruby-1.4.0/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
        from script\generate:3

I don't know why this is happening. Everything worked fine in 2.3.2 and now it doesn't.

---

Activesupport gem is not installed on your machine. Try running this command:

gem install activesupport

Incase it doesn't work, try this

gem update --system
gem update --source http://gems.rubyonrails.org

---

Well I could solve this by placing the following line(written below) once the Rails::Initializer.run do |config| block ends(it was inside this block before).

ActiveSupport::CoreExtensions::Time::Conversions::DATE_FORMATS.merge!(:standard => "%B %d, %Y")