Rails Console Not Loading

I had this couple of days ago. You can try to reinstall/recompile your ruby. In my case problem appeared when updating from El Capitan to Sierra

so depending on your manager:

RVM

rvm reinstall 2.3.0

Rbenv

rbenv uninstall 2.3.0
rbenv install 2.3.0

asdf

asdf uninstall ruby 2.3.0
asdf install ruby 2.3.0

Looking elsewhere, none of the re-linking options worked. It was suggested to redo the rvm installation (which seems onerous). However, simply adding readline into the Gemfile works for me:

gem 'rb-readline'

It could be that there are multiple versions of readline installed.

Try the following:

brew link readline --force