bcrypt LoadError: Cannot load such file

Question

I'm trying to set up a login function for my Rails app, I'm getting a bcrypt error message when I press the login button:

LoadError in SessionsController#create
cannot load such file -- bcrypt

Is anyone else getting this error? I have the latest version of bcrypt and I'm following exactly what the tutorial told me to do.

User Model: I put asterisks around the line where the error allegedly is.

class User < ActiveRecord::Base
  ****has_secure_password****
end

Sessions Controller:

class SessionsController < ApplicationController
  def new
  end

  def create
    user = User.find_by(id: params[session][:id])
    if user && user.authenticate(params[:session][:password])
      log_in user
      redirect_to root_path
    else
      flash.now[:danger] = 'Invalid'
      render 'new'
    end
  end

  def destroy
  end
end

ApplicationController:

class ApplicationController < ActionController::Base
  protect_from_forgery with: :exception
  include SessionsHelper
end

SessionsHelper:

module SessionsHelper

  def log_in(user)
    session[:user_id] = user.id
  end
end

Gemfile:

gem 'bcrypt', '~> 3.1.7'

Sessions/new View:

<div id= "admin-sign-in">
  <%= form_for(:session, url: login_path) do |f| %>

    <%= f.label :id %>
    <%= f.text_field :id %>

    <%= f.label :password %>
    <%= f.password_field :password %>

    <%= f.submit "Log in", class: "btn btn-primary" %>
  <% end %>
</div>

Answer 1

after running bundle install to install bcrypt, do not forget to restart the rails server.
It worked for me.