Simple Rails App: Error Cannot visit Integer

Question

I am trying to build a simple Rails app. Rails v3.2.22.5 (it is a requirement). I am running it with PostgreSQL. When I start the server however I get the following error wh

Answer 1

The version of Ruby you're using (2.4.1) is not compatible with the version of Rails you're using (3.2.22.5). That version of Ruby requires at least Rails 5. Try downgrading to Ruby 2.3 or lower. You can use a Ruby version manager (i.e. rvm, rbenv or chruby) to control which Ruby is used when launching your application.

Edit

Just noticed you're already using rbenv from your stack trace. Add a .ruby-version file to your application's directory containing the following line:

2.3.4

Once you re-enter that directory, confirm the version via:

$> ruby -v
ruby 2.3.4p301 (2017-03-30 revision 58214) [x86_64-darwin16]

(or similar version) before launching rails.