gem install error for activesupport - wrong version

I installed rails 2.1.0
I updated my gems with the following commands

gem update --system
gem update --source

But when I run ruby script/server, I get the following error:

error': RubyGem version error: activesupport(2.1.0 not = 1.4.2)

Yes, my active support is not 1.4.2 as I updated it to 2.1.0. What can
I do here.


Changed environment.rb to

RAILS_GEM_VERSION = '2.1.0' unless defined? RAILS_GEM_VERSION

and it worked.