asdf message "No version set for command rails" when running Rails server

I am trying to run my rails server (rails s) in my Rails 3.2.13 application after having updated my Ruby version in /.ruby-version and /.tools-versions, but get the following message:

`you might want to add one of the following in your .tool-versions file:

ruby 2.2.4`

However, I had updated ruby in both version files to 2.3.0 and it is reflected in both. When I type asdf which ruby the ruby version is also 2.3.0.

I'd like help understanding why rails s prompts this asdf message, and what I'm missing with how to fix it so that I can run the rails server.