HI, i am working in Rails .. my gem list is
*** LOCAL GEMS ***
abstract (1.0.0)
actionmailer (3.0.4, 3.0.3, 2.3.11, 2.3.10, 2.3.8, 2.3.4, 2.3.2)
action
I know there's already an answer for this, but when I was running an older rails, I specified script/server webrick after having the same problem and this worked. This may not be ideal for production, however, and I recommend upgrading as mentioned in the other answer.
This is happening because you installed RubyGems that is too new for your version of Rails. Either downgrade (and re-run update_rubygems) or upgrade Rails to 2.3.11.
This could be because you have rails 3 installed but are trying to run a rails 2.3.4 app. I've had this problem before and the solution was to remove rails 3 because this dependency is one of rails 3, not 2.3.4
The solution is fairly simple. Just run the following commands to go back to the previous version of rubygems and you should be fine:
$ gem install rubygems-update -v='1.4.2'
$ gem uninstall rubygems-update -v='1.5.0'
$ update_rubygems
Your gem list (the one you get on the command "gem list") is list of installed gems.
That's not the list of gems used by your application -> those are in the Gemfile.
Things you might try or have tried:
(see also https://gist.github.com/807008 )
OK I just upgraded a Rails app from 2.3.4 to 2.3.14 and got the same error.
However I had already downgraded rubygems to 1.3.5 (as recommended in another answer) to get around a similar error after upgrading the core Ruby package
So i took a punt and upgraded to the latest version:
sudo gem update --system
This gave me version 1.8.24
and everything started working again. shrug
Perhaps that throws the issue into a somewhat different light.