title: Rails 3: "uninitialized constant Formtastic::FormBuilder" error after deploying app on production server
body: <p>I am trying to deploy my Rails3.0 application on production server. There was many troubles before, but all of them solved. And now I have another.</p>
  
  <p>There is a passenger error page's text:</p>
  
  <p><strong>Error message:</strong>
  uninitialized constant Formtastic::FormBuilder</p>
  
  <p><strong>Exception class:</strong>
  NameError</p>
  
  <p><strong>Backtrace:</strong></p>
  
  <p>0   /home/ubuntu/.rvm/gems/ruby-1.9.2-p180@rails3.0/gems/client_side_validations-3.1.0/lib/client_side_validations/formtastic.rb    20  in `'</p>
  
  <p>1   /home/ubuntu/projects/questroad/config/initializers/client_side_validations.rb  4   in <code>'
  2   /home/ubuntu/.rvm/gems/ruby-1.9.2-p180@rails3.0/gems/railties-3.0.7/lib/rails/engine.rb 201 in</code>block (2 levels) in '</p>
  
  <p>3   /home/ubuntu/.rvm/gems/ruby-1.9.2-p180@rails3.0/gems/railties-3.0.7/lib/rails/engine.rb 200 in `each'</p>
  
  <p>...</p>
  
  <p>Google search results not helped me, and now I am here.</p>
  
  <p><strong>UPD:</strong>
  Also if i try to run WEBrick server there was the same error.</p>
  
  <p><strong>UPD:</strong>
  I try to comment "gem 'client_side_validation'" line in Gemfile, and error is disappeared. But now i cant use this gem.</p>