Could not railties in mac os - ruby-on-rails

Question

I had recently followed multiple blogs to completely wipe out rvm, rails and then reinstalled ruby 2.3.0 and rails 5. Made and app using it no issues. But the moment I opened a new terminal window in my machine it was not recognising rails at all as if it was only installed in that particular terminal.
So I just completed my work in that single terminal. Now when I restarted my laptop, I am unable to run the same app. I do not wish to reinstall everything again as I am sure this is a small configuration problem. Why is this happening?
The error message that I am getting now:
/Users/sahil/.rbenv/versions/2.3.1/lib/ruby/2.3.0/rubygems/dependency.rb:319:in `to_specs': Could not find 'railties' (>= 0.a) among 30 total gem(s) (Gem::LoadError)
Checked in 'GEM_PATH=/Users/sahil/.rvm/gems/ruby-2.3.1:/Users/sahil/.rvm/gems/ruby-2.3.1#global', execute `gem env` for more information
from /Users/sahil/.rbenv/versions/2.3.1/lib/ruby/2.3.0/rubygems/dependency.rb:328:in `to_spec'
from /Users/sahil/.rbenv/versions/2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_gem.rb:65:in `gem'
from /Users/sahil/.rbenv/versions/2.3.1/bin/rails:22:in `<main>'
I have already seen other similar questions where they ask to reinstall everything again which I do not want to do as it worked after installing but did not work on system restart.
Now I did gem install rails in one terminal and the app is working again, but if I try to open a new terminal and give the same command rails s, it gives me this error,
Ignoring byebug-9.0.5 because its extensions are not built. Try: gem pristine byebug --version 9.0.5
Ignoring debug_inspector-0.0.2 because its extensions are not built. Try: gem pristine debug_inspector --version 0.0.2
Ignoring nokogiri-1.6.8 because its extensions are not built. Try: gem pristine nokogiri --version 1.6.8
Ignoring byebug-9.0.5 because its extensions are not built. Try: gem pristine byebug --version 9.0.5
Ignoring debug_inspector-0.0.2 because its extensions are not built. Try: gem pristine debug_inspector --version 0.0.2
/Users/sahil/.rbenv/versions/2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require': incompatible library version - /Users/sahil/.rvm/gems/ruby-2.3.1#global/gems/io-console-0.4.6/lib/io/console.bundle (fatal)
from /Users/sahil/.rbenv/versions/2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Users/sahil/.rbenv/versions/2.3.1/lib/ruby/2.3.0/rubygems/user_interaction.rb:9:in `<top (required)>'
from /Users/sahil/.rbenv/versions/2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Users/sahil/.rbenv/versions/2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Users/sahil/.rbenv/versions/2.3.1/lib/ruby/2.3.0/rubygems/config_file.rb:8:in `<top (required)>'
from /Users/sahil/.rbenv/versions/2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Users/sahil/.rbenv/versions/2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Users/sahil/.rvm/gems/ruby-2.3.1#global/gems/bundler-1.12.5/lib/bundler/rubygems_integration.rb:4:in `<top (required)>'
from /Users/sahil/.rbenv/versions/2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Users/sahil/.rbenv/versions/2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Users/sahil/.rvm/gems/ruby-2.3.1#global/gems/bundler-1.12.5/lib/bundler/shared_helpers.rb:6:in `<top (required)>'
from /Users/sahil/.rbenv/versions/2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Users/sahil/.rbenv/versions/2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Users/sahil/.rvm/gems/ruby-2.3.1#global/gems/bundler-1.12.5/lib/bundler/setup.rb:2:in `<top (required)>'
from /Users/sahil/.rbenv/versions/2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:127:in `require'
from /Users/sahil/.rbenv/versions/2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:127:in `rescue in require'
from /Users/sahil/.rbenv/versions/2.3.1/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:40:in `require'
from /Users/sahil/Documents/work/Development/todoApp/config/boot.rb:3:in `<top (required)>'
from bin/rails:3:in `require_relative'
from bin/rails:3:in `<main>'

Answer 1

You mentioned that you reinstalled ruby 2.3.0 and Rails 5. However it seems rbenv is trying to load your project with ruby 2.3.1.
You should switch to ruby 2.3.0. I guess you should be able to do: rbenv local 2.3.0.
To avoid this from happening again though, you should add a .ruby-version dotfile to your project root and in the file only add 2.3.0.
Hope that works