bootstrapのreadmeに沿ってインストールしていますが、何故かエラーが出ます。色々調べたりもしましたが、CSSのRuntimeErrorはあまり見当たらなかったので、困りました。
エラーメッセージがhtmlの埋め込みルビーを参照してるので、記述が間違っているのかとも思いましたが、rails newしてからいじってないですし、記法を検索もしましたが、問題ないような気がします。どなたか見当がつきそうな方がいましたら、アドバイスお願いします。

gemfile

source 'https://rubygems.org'

gem 'rails',           '~> 5.1.6'
gem 'sqlite3'
gem 'puma',            '~> 3.7'
gem 'bootstrap',       '~> 4.1.3'
gem 'sass-rails',      '~> 5.0'
gem 'uglifier',        '>= 1.3.0'
gem 'coffee-rails',    '~> 4.2'
gem 'turbolinks',      '~> 5'
gem 'jbuilder',        '~> 2.5'
gem 'sprockets-rails', '3.2.1'
gem 'jquery-rails'


group :development, :test do
  gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
  gem 'capybara', '~> 2.13'
  gem 'selenium-webdriver'
end

group :development do
  gem 'web-console', '>= 3.3.0'
  gem 'listen', '>= 3.0.5', '< 3.2'
  gem 'spring'
  gem 'spring-watcher-listen', '~> 2.0.0'
end

group :test do
  gem 'rails-controller-testing', '1.0.2'
  gem 'minitest',                 '5.10.3'
  gem 'minitest-reporters',       '1.1.14'
  gem 'guard',                    '2.13.0'
  gem 'guard-minitest',           '2.4.4'
end


# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]

application.scss

// Custom bootstrap variables must be set or imported *before* bootstrap.
@import "bootstrap";

application.js

// This is a manifest file that'll be compiled into application.js, which will include all the files
// listed below.
//
// Any JavaScript/Coffee file within this directory, lib/assets/javascripts, or any plugin's
// vendor/assets/javascripts directory can be referenced here using a relative path.
//
// It's not advisable to add code directly here, but if you do, it'll appear at the bottom of the
// compiled file. JavaScript code in this file should be added after the last require_* statement.
//
// Read Sprockets README (https://github.com/rails/sprockets#sprockets-directives) for details
// about supported directives.
//
//= require rails-ujs
//= require turbolinks
//= require_tree .
//= require jquery3
//= require popper
//= require bootstrap-sprockets

application.html.erb

<!DOCTYPE html>
<html>
  <head>
    <title>MyApp</title>
    <%= csrf_meta_tags %>

    <%= stylesheet_link_tag    'application', media: 'all', 'data-turbolinks-track': 'reload' %>
    <%= javascript_include_tag 'application', 'data-turbolinks-track': 'reload' %>
  </head>

  <body>
    <%= yield %>
  </body>
</html>

error message