title: Cannot run rails server -- `require``main`
body: <p>On mac, when running: <code>rails server</code>, the error below appears:</p>
  
  <pre><code>/Users/KimiebiAkah/Desktop/Rails_App/feastonline/config/application.rb:12:in `require': cannot load such file -- iconv (LoadError)
          from /Users/KimiebiAkah/Desktop/Rails_App/feastonline/config/application.rb:12:in `&lt;top (required)&gt;'
          from /Users/KimiebiAkah/.rvm/gems/ruby-2.3.0/gems/railties-4.2.6/lib/rails/commands/commands_tasks.rb:78:in `require'
          from /Users/KimiebiAkah/.rvm/gems/ruby-2.3.0/gems/railties-4.2.6/lib/rails/commands/commands_tasks.rb:78:in `block in server'
          from /Users/KimiebiAkah/.rvm/gems/ruby-2.3.0/gems/railties-4.2.6/lib/rails/commands/commands_tasks.rb:75:in `tap'
          from /Users/KimiebiAkah/.rvm/gems/ruby-2.3.0/gems/railties-4.2.6/lib/rails/commands/commands_tasks.rb:75:in `server'
          from /Users/KimiebiAkah/.rvm/gems/ruby-2.3.0/gems/railties-4.2.6/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
          from /Users/KimiebiAkah/.rvm/gems/ruby-2.3.0/gems/railties-4.2.6/lib/rails/commands.rb:17:in `&lt;top (required)&gt;'
          from bin/rails:4:in `require'
          from bin/rails:4:in `&lt;main&gt;'
  </code></pre>
  
  <p>I do not know what is wrong with the app. 
  How can this be alleviated?</p>
  
  <p><em>gemfile:</em></p>
  
  <pre><code>source 'http://rubygems.org'
  ruby '2.3.0'  # '1.9.3'
  
  gem 'rails', '4.2.6'
  gem 'mysql2', '0.4.4'
  gem 'bootstrap-sass', '2.3.2.0'
  gem 'bcrypt-ruby', '3.1.2'
  gem 'faker', '1.1.2'
  gem 'will_paginate', '3.0.4'
  gem 'bootstrap-will_paginate', '0.0.9'
  gem 'geocoder', '1.1.8'
  gem 'nested_form', '0.3.2'
  gem 'utf8-cleaner', '0.0.6'
  gem 'sprockets', '2.11.0'
  gem 'json', '1.8.3'
  gem 'ffi'
  
  gem 'chosen-rails', '1.0.1'
  gem 'compass-rails', github: 'Compass/compass-rails'
  
  # For image uploads
  gem 'carrierwave', '0.9.0'
  
  # For uploading CSV
  gem 'roo', '1.13.2'
  
  # DataTables
  gem 'jquery-datatables-rails', '2.2.3' #  git: 'git://github.com/rweng/jquery-datatables-rails.git'
  gem 'jquery-ui-rails', '5.0.2'
  
  # Editing in line:
  gem 'best_in_place', '3.0.3'
  
  # Passing data from controller to coffeescript
  gem 'gon', '5.2.3'
  
  gem 'progress_bar', '1.0.0'
  
  # Calendar Date and Validation
  gem 'bootstrap-datepicker-rails'
  
  # For Google Maps overlays
  gem 'gmaps4rails', '~&gt; 2.1.2'
  gem 'underscore-rails', '~&gt; 1.7.0'
  
  group :development, :test do
    gem 'rspec-rails', '2.13.1'
    gem 'guard-rspec', '2.5.0'
    gem 'spork-rails', '4.0.0'
    gem 'childprocess', '0.3.9'
    gem 'guard-spork', '1.5.0'
  end
  
  group :test do
    gem 'selenium-webdriver', '2.35.1'
    gem 'capybara', '2.1.0'
    gem 'factory_girl_rails', '4.2.1'
  end
  
  gem 'sass-rails', '4.0.1'
  gem 'uglifier', '2.1.1'
  gem 'coffee-rails', '4.1.0'
  gem 'jquery-rails', '3.1.2'
  gem 'turbolinks', '1.1.1'
  gem 'jbuilder', '1.0.2'
  
  group :doc do
    gem 'sdoc', '0.3.20', require: false
  end
  
  gem 'rails_12factor', '0.0.3'
  </code></pre>