Bundler could not find compatible versions for gem “railties” for Rails 4.0.0

Question

I am trying to upgrade to Rails 4.0.0, and I changed the gem versions of sass-rails and coffee-rails. I need to resolve this gem conflict between <

Answer 1

You have gems that aren't supported by Rails 4. Comment out all the gems except for Rails 4 and uncomment them one at a time after running bundle install to find the culprits. You might need to undo some of your version locks.