I just now my rails app to rails 4 from rails 3. I am not able to get it to work. I have done all the necessary configuration removal and addition whereever necessary. But now I am facing this. IS the question too blunt? IF so comment on what information is needed to make it more understandable. I am a totally new to rails, please help.

```
/home/aravind/Documents/dev/ptl/config/initializers/simple_form.rb:8:in `block in <top (required)>': undefined method `wrappers' for SimpleForm:Module (NoMethodError)
from /usr/local/lib/ruby/gems/2.0.0/gems/simple_form-1.4.1/lib/simple_form.rb:143:in `setup'
from /home/aravind/Documents/dev/ptl/config/initializers/simple_form.rb:2:in `<top (required)>'
from /usr/local/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:222:in `load'
from /usr/local/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:222:in `block in load'
from /usr/local/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:213:in `load_dependency'
from /usr/local/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:222:in `load'
from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/engine.rb:609:in `block (2 levels) in <class:Engine>'
from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/engine.rb:608:in `each'
from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/engine.rb:608:in `block in <class:Engine>'
from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `instance_exec'
from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `run'
from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/initializable.rb:55:in `block in run_initializers'
from /usr/local/lib/ruby/2.0.0/tsort.rb:150:in `block in tsort_each'
from /usr/local/lib/ruby/2.0.0/tsort.rb:183:in `block (2 levels) in each_strongly_connected_component'
from /usr/local/lib/ruby/2.0.0/tsort.rb:210:in `block (2 levels) in each_strongly_connected_component_from'
from /usr/local/lib/ruby/2.0.0/tsort.rb:219:in `each_strongly_connected_component_from'
from /usr/local/lib/ruby/2.0.0/tsort.rb:209:in `block in each_strongly_connected_component_from'
from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/initializable.rb:44:in `each'
from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/initializable.rb:44:in `tsort_each_child'
from /usr/local/lib/ruby/2.0.0/tsort.rb:203:in `each_strongly_connected_component_from'
from /usr/local/lib/ruby/2.0.0/tsort.rb:182:in `block in each_strongly_connected_component'
from /usr/local/lib/ruby/2.0.0/tsort.rb:180:in `each'
from /usr/local/lib/ruby/2.0.0/tsort.rb:180:in `each_strongly_connected_component'
from /usr/local/lib/ruby/2.0.0/tsort.rb:148:in `tsort_each'
from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/initializable.rb:54:in `run_initializers'
from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/application.rb:215:in `initialize!'
from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/railtie/configurable.rb:30:in `method_missing'
from /home/aravind/Documents/dev/ptl/config/environment.rb:5:in `<top (required)>'
from /usr/local/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require'
from /usr/local/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `block in require'
from /usr/local/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:213:in `load_dependency'
from /usr/local/lib/ruby/gems/2.0.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require'
from /home/aravind/Documents/dev/ptl/config.ru:3:in `block in <main>'
from /usr/local/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb:55:in `instance_eval'
from /usr/local/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb:55:in `initialize'
from /home/aravind/Documents/dev/ptl/config.ru:in `new'
from /home/aravind/Documents/dev/ptl/config.ru:in `<main>'
from /usr/local/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb:49:in `eval'
from /usr/local/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb:49:in `new_from_string'
from /usr/local/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/builder.rb:40:in `parse_file'
from /usr/local/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/server.rb:277:in `build_app_and_options_from_config'
from /usr/local/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/server.rb:199:in `app'
from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/commands/server.rb:48:in `app'
from /usr/local/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/server.rb:314:in `wrapped_app'
from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/commands/server.rb:75:in `start'
from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/commands.rb:78:in `block in <top (required)>'
from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/commands.rb:73:in `tap'
from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/commands.rb:73:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'

```