Redmine

Hello all! I would like to create my own plugin, but when I do this:

rails g redmine_plugin my_own_plugin

I see: /Users/crashcube/.rbenv/versions/1.9.3-p362/lib/ruby/gems/1.9.1/gems/activesupport-3.2.9/lib/active_support/dependencies.rb:251:in `require': cannot load such file -- dispatcher (LoadError)

This error raises on any rails g commands. Redmine version is 2.2.