title: hey i m new in ruby on rails and I get error while executing rails s?
body: <pre><code>ajay@ajay-Inspiron-9300:~/ruby_rails_practical_demo/ftuse/ft1$ rails s
  =&gt; Booting WEBrick
  =&gt; Rails 4.0.0 application starting in development on http:0.0.0.0:3000
  =&gt; Run `rails server -h` for more startup options
  =&gt; Ctrl-C to shutdown server
  Exiting
  /usr/lib/ruby/gems/1.9.1/gems/activesupport 4.0.0/lib/active_support/inflector/methods.rb:226:in `const_get': uninitialized constant Wellcome (NameError)
  from /usr/lib/ruby/gems/1.9.1/gems/activesupport 4.0.0/lib/active_support/inflector/methods.rb:226:in `block in constantize'
      from /usr/lib/ruby/gems/1.9.1/gems/activesupport-4.0.0/lib/active_support/inflector/methods.rb:224:in `each'
      from /usr/lib/ruby/gems/1.9.1/gems/activesupport-4.0.0/lib/active_support/inflector/methods.rb:224:in `inject'
      from /usr/lib/ruby/gems/1.9.1/gems/activesupport-4.0.0/lib/active_support/inflector/methods.rb:224:in `constantize'
      from /usr/lib/ruby/gems/1.9.1/gems/devise-3.1.0/lib/devise.rb:285:in `get'
      from /usr/lib/ruby/gems/1.9.1/gems/devise-3.1.0/lib/devise/mapping.rb:77:in `to'
      from /usr/lib/ruby/gems/1.9.1/gems/devise-3.1.0/lib/devise/mapping.rb:72:in `modules'
      from /usr/lib/ruby/gems/1.9.1/gems/devise-3.1.0/lib/devise/mapping.rb:89:in `routes'
      from /usr/lib/ruby/gems/1.9.1/gems/devise-3.1.0/lib/devise/mapping.rb:156:in `default_used_route'
      from /usr/lib/ruby/gems/1.9.1/gems/devise-3.1.0/lib/devise/mapping.rb:66:in `initialize'
      from /usr/lib/ruby/gems/1.9.1/gems/devise-3.1.0/lib/devise.rb:319:in `new'
      from /usr/lib/ruby/gems/1.9.1/gems/devise-3.1.0/lib/devise.rb:319:in `add_mapping'
      from /usr/lib/ruby/gems/1.9.1/gems/devise-3.1.0/lib/devise/rails/routes.rb:210:in `block in devise_for'
      from /usr/lib/ruby/gems/1.9.1/gems/devise-3.1.0/lib/devise/rails/routes.rb:209:in `each'
      from /usr/lib/ruby/gems/1.9.1/gems/devise-3.1.0/lib/devise/rails/routes.rb:209:in `devise_for'
      from /home/ajay/ruby_rails_practical_demo/ftuse/ft1/config/routes.rb:2:in `block in &lt;top (required)&gt;'
      from /usr/lib/ruby/gems/1.9.1/gems/actionpack-4.0.0/lib/action_dispatch/routing/route_set.rb:316:in `instance_exec'
      from /usr/lib/ruby/gems/1.9.1/gems/actionpack-4.0.0/lib/action_dispatch/routing/route_set.rb:316:in `eval_block'
      from /usr/lib/ruby/gems/1.9.1/gems/actionpack-4.0.0/lib/action_dispatch/routing/route_set.rb:294:in `draw'
      from /home/ajay/ruby_rails_practical_demo/ftuse/ft1/config/routes.rb:1:in `&lt;top (required)&gt;'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:40:in `block in load_paths'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:40:in `each'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:40:in `load_paths'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:16:in `reload!'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:26:in `block in updater'
      from /usr/lib/ruby/gems/1.9.1/gems/activesupport-4.0.0/lib/active_support/file_update_checker.rb:75:in `call'
      from /usr/lib/ruby/gems/1.9.1/gems/activesupport-4.0.0/lib/active_support/file_update_checker.rb:75:in `execute'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:27:in `updater'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:6:in `execute_if_updated'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/application/finisher.rb:69:in `block in &lt;module:Finisher&gt;'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `instance_exec'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `run'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/initializable.rb:55:in `block in run_initializers'
      from /usr/lib/ruby/1.9.1/tsort.rb:150:in `block in tsort_each'
      from /usr/lib/ruby/1.9.1/tsort.rb:183:in `block (2 levels) in each_strongly_connected_component'
      from /usr/lib/ruby/1.9.1/tsort.rb:219:in `each_strongly_connected_component_from'
      from /usr/lib/ruby/1.9.1/tsort.rb:182:in `block in each_strongly_connected_component'
      from /usr/lib/ruby/1.9.1/tsort.rb:180:in `each'
      from /usr/lib/ruby/1.9.1/tsort.rb:180:in `each_strongly_connected_component'
      from /usr/lib/ruby/1.9.1/tsort.rb:148:in `tsort_each'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/initializable.rb:54:in `run_initializers'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/application.rb:215:in `initialize!'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/railtie/configurable.rb:30:in `method_missing'
      from /home/ajay/ruby_rails_practical_demo/ftuse/ft1/config/environment.rb:5:in `&lt;top (required)&gt;'
      from /home/ajay/ruby_rails_practical_demo/ftuse/ft1/config.ru:3:in `block in &lt;main&gt;'
      from /usr/lib/ruby/gems/1.9.1/gems/rack-1.5.2/lib/rack/builder.rb:55:in `instance_eval'
      from /usr/lib/ruby/gems/1.9.1/gems/rack-1.5.2/lib/rack/builder.rb:55:in `initialize'
      from /home/ajay/ruby_rails_practical_demo/ftuse/ft1/config.ru:in `new'
      from /home/ajay/ruby_rails_practical_demo/ftuse/ft1/config.ru:in `&lt;main&gt;'
      from /usr/lib/ruby/gems/1.9.1/gems/rack-1.5.2/lib/rack/builder.rb:49:in `eval'
      from /usr/lib/ruby/gems/1.9.1/gems/rack-1.5.2/lib/rack/builder.rb:49:in `new_from_string'
      from /usr/lib/ruby/gems/1.9.1/gems/rack-1.5.2/lib/rack/builder.rb:40:in `parse_file'
      from /usr/lib/ruby/gems/1.9.1/gems/rack-1.5.2/lib/rack/server.rb:277:in `build_app_and_options_from_config'
      from /usr/lib/ruby/gems/1.9.1/gems/rack-1.5.2/lib/rack/server.rb:199:in `app'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/commands/server.rb:48:in `app'
      from /usr/lib/ruby/gems/1.9.1/gems/rack-1.5.2/lib/rack/server.rb:314:in `wrapped_app'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/commands/server.rb:75:in `start'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/commands.rb:78:in `block in &lt;top (required)&gt;'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/commands.rb:73:in `tap'
      from /usr/lib/ruby/gems/1.9.1/gems/railties-4.0.0/lib/rails/commands.rb:73:in `&lt;top (required)&gt;'
      from bin/rails:4:in `require'
      from bin/rails:4:in `&lt;main&gt;'
  </code></pre>