Forum: Ruby on Rails bootstrap :File to import not found or unreadable

Hello!
I have found alredy some topics about my problem but I didnt understand 
how
it should be fixed. Sorry =)

I was following
http://ruby.railstutorial.org/chapters/filling-in-... 
tutorial
and stuck by importing the bootstrap in
app/assets/stylesheets/custom.css.scss.

That is my Gemfile:

source 'https://rubygems.org'

gem 'bootstrap-sass', '2.0.4'

gem 'rails', '3.2.8'

group :development, :test do

gem 'sqlite3', '1.3.5'

gem 'rspec-rails', '2.11.0'

end


group :assets do

gem 'sass-rails', '3.2.5'

gem 'coffee-rails', '3.2.2'

gem 'uglifier', '1.2.3'

end

gem 'jquery-rails', '2.0.2'

group :test do

gem 'capybara', '1.1.2'

end

group :production do

gem 'pg', '0.12.2'

end

And what error I get on localhost/sample_app/home

Sass::SyntaxError in Static_pages#home

Showing
c:/Users/katja/Arbeit/rails_projects/sample_app/app/views/layouts/application.html.erb
where line #5 
<https://github.com/thomas-mcdonald/bootstrap-sass/...
 raised:

File to import not found or unreadable: bootstrap.

Load path:
Sass::Rails::Importer(c:/Users/katja/Arbeit/rails_projects/sample_app/app/assets/stylesheets/custom.css.scss)

(in
c:/Users/katja/Arbeit/rails_projects/sample_app/app/assets/stylesheets/custom.css.scss)

Extracted source (around line 
#5<https://github.com/thomas-mcdonald/bootstrap-sass/...
):

2:

3:

4: <%= full_title(yield(:title)) %>

5: <%= stylesheet_link_tag "application", media: "all" %>

6: <%= javascript_include_tag "application" %>

7: <%= csrf_meta_tags %>

8: <!--[if lt IE 9]>

Rails.root: c:/Users/katja/Arbeit/rails_projects/sample_app

Application Trace | Framework Trace | Full Trace

app/assets/stylesheets/custom.css.scss:1

app/views/layouts/application.html.erb:5:in
`app_views_layouts_application_html_erb_16020705_20168520'



I have tried to remove tmp/cache folder, it didnt help.

Everything works before adding @import "bootstrap"; into 
custom.css.scss.
After it works nothing.


Thank you in Advanced