How to fix template error "CoffeeScript not defined" - ruby-on-rails

Question

I am trying to get the view for my project to show up. but I get this error:
ActionView::Template::Error (ReferenceError: CoffeeScript is not defined):
4: <title>Myapp</title>
5: <%= csrf_meta_tags %>
6:
7: <%= stylesheet_link_tag 'application', media: 'all', 'data-turbolinks-track': 'reload' %>
8: <%= javascript_include_tag 'application', 'data-turbolinks-track': 'reload' %>
9: </head>
10:
When I remove lines 7-8 then it works, but I would have no CSS, or JavaScript.
I did not receive this error about a week ago. I'm not sure what the cause is. I tried switching Rails versions. I've tried uninstalling Postgres and setting it up again, but it does not seem to be the issue.
I have Rails 5.0.0.1, and "Ruby 2.3.3p222 (2016-11-21 revision 56859) [x86_64-darwin16]". Also I'm using Mac OS Sierra.
I could change the 'application' to 'default' and it works, but I don't understand why it worked about a week ago, and not now.
I also have my view and controller set up, which is the reason why it works when i remove lines 7-8.
This is my gem file:
source 'https://rubygems.org'
# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '~> 5.0.0', '>= 5.0.0.1'
# Use postgresql as the database for Active Record
gem 'pg', '~> 0.18'
# Use Puma as the app server
gem 'puma', '~> 3.0'
# Use SCSS for stylesheets
gem 'sass-rails', '~> 5.0'
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'
# Use CoffeeScript for .coffee assets and views
gem 'coffee-rails', '~> 4.2'
# See https://github.com/rails/execjs#readme for more supported runtimes
# gem 'therubyracer', platforms: :ruby
# Use jquery as the JavaScript library
gem 'jquery-rails'
# Turbolinks makes navigating your web application faster. Read more: https://github.com/turbolinks/turbolinks
gem 'turbolinks', '~> 5'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.5'
# Use Redis adapter to run Action Cable in production
# gem 'redis', '~> 3.0'
# Use ActiveModel has_secure_password
# gem 'bcrypt', '~> 3.1.7'
# Use Capistrano for deployment
# gem 'capistrano-rails', group: :development
group :development, :test do
# Call 'byebug' anywhere in the code to stop execution and get a debugger console
gem 'byebug', platform: :mri
end
group :development do
# Access an IRB console on exception pages or by using <%= console %> anywhere in the code.
gem 'web-console'
gem 'listen', '~> 3.0.5'
# Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
gem 'spring'
gem 'spring-watcher-listen', '~> 2.0.0'
end
# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]

Answer 1

There is a problem in coffe-script-source gem 1.12.1 which was recently updated. the issue is that the source file in this version is empty. there is already an open issue , and it should be fixed soon.
For now you can add this to your GemFile
gem 'coffee-script-source', '= 1.11.1'
and run bundle update coffee-script-source until it's fixed.

Answer 2

I also had to use gem uninstall coffee-script-source, then gem install coffee-script-source ... as my gemfile.lock wasn't updating no matter how many times I did 'bundle install' or 'bundle update' after removing coffe-script & coffee-script-source entries in the gemfile.