LoadError in Devise::RegistrationsController#create - ruby-on-rails

Question

I am using the gem of devise and I am getting error LoadError in Devise::RegistrationsController#create cannot load such file -- bcrypt_ext.. I tried to do some research regarding to this problem and also tried to follow the instruction given(https://stackoverflow.com/questions/35422463/loaderror-in-deviseregistrationscontrollercreate-cannot-load-such-file-bc)
But still having this problem. Any suggestion?
NOTE: The guide that I am using is video guide and I am using ruby on rails on windows 7
Gem File
source 'https://rubygems.org'
git_source(:github) do |repo_name|
repo_name = "#{repo_name}/#{repo_name}" unless repo_name.include?("/")
"https://github.com/#{repo_name}.git"
end
# error in devise
gem 'bcrypt-ruby', '~> 3.1', '>= 3.1.5'
# Bundle for authentication
gem 'devise', '~> 4.2', '>= 4.2.1'
# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '~> 5.1.0.rc1'
# Use postgresql as the database for Active Record
gem 'pg', '~> 0.18'
# Use Puma as the app server
gem 'puma', '~> 3.7'
# Use SCSS for stylesheets
gem 'sass-rails', github: "rails/sass-rails"
# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'
# See https://github.com/rails/execjs#readme for more supported runtimes
# gem 'therubyracer', platforms: :ruby
# Use CoffeeScript for .coffee assets and views
gem 'coffee-rails', '~> 4.2'
# Turbolinks makes navigating your web application faster. Read more: https://github.com/turbolinks/turbolinks
gem 'turbolinks', '~> 5'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.5'
# Use Redis adapter to run Action Cable in production
# gem 'redis', '~> 3.0'
# Use ActiveModel has_secure_password
# gem 'bcrypt', '~> 3.1.7'
# Use Capistrano for deployment
# gem 'capistrano-rails', group: :development
group :development, :test do
# Call 'byebug' anywhere in the code to stop execution and get a debugger console
gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
# Adds support for Capybara system testing and selenium driver
gem 'capybara', '~> 2.13.0'
gem 'selenium-webdriver'
end
group :development do
# Access an IRB console on exception pages or by using <%= console %> anywhere in the code.
gem 'web-console', '>= 3.3.0'
end
# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]

Answer 1

I was also having the same error, and my problem got fixed, please try solution 3
The problem is the compiled windows gem. It would be better if it were deleted and only include the pure ruby version.
Solution one:
You can copy bcrypt_ext.so from \lib\2.1 to \lib the same folder where is bcrypt.rb
Solution two:
You can use the gem install bcrypt --platform=ruby even if I had trouble to select that from rails which it always use the compiled version
Solution three:
git clone https://github.com/codahale/bcrypt-ruby.git
cd bcrypt-ruby
gem build bcrypt.gemspec
gem install gem-compiler
gem compile bcrypt-3.1.10.gem
gem install bcrypt-3.1.10-x64-mingw32.gem --local

Answer 2

Please do one thing and it will solve your problem
remove the version and rest just write this in your Gemfile
gem 'bcrypt-ruby'