ruby on rails - Routing Error: No route matches [GET] "/users/sign_up" -

i new stackoverflow , i'm learning ruby on rails. can't solve problem od localhost: no route matches [get] "/ users / sign_up" (devise gem).

here code:

routes.rb:

rails.application.routes.draw    resources :posts     resources :comments   end    root 'posts#index'    '/about' => 'pages#about'  end 

in config/development.rb added:

config.action_mailer.default_url_options = { host: 'localhost', port: 3000 } 

rake routes shows:

post_comments_path  /posts/:post_id/comments(.:format)  comments#index                     post    /posts/:post_id/comments(.:format)  comments#create new_post_comment_path   /posts/:post_id/comments/new(.:format)  comments#new edit_post_comment_path  /posts/:post_id/comments/:id/edit(.:format) comments#edit post_comment_path   /posts/:post_id/comments/:id(.:format)  comments#show                     patch   /posts/:post_id/comments/:id(.:format)  comments#update                     put /posts/:post_id/comments/:id(.:format)  comments#update                     delete  /posts/:post_id/comments/:id(.:format)  comments#destroy posts_path  /posts(.:format)    posts#index                     post    /posts(.:format)    posts#create new_post_path   /posts/new(.:format)    posts#new edit_post_path  /posts/:id/edit(.:format)   posts#edit post_path   /posts/:id(.:format)    posts#show                     patch   /posts/:id(.:format)    posts#update                     put /posts/:id(.:format)    posts#update                     delete  /posts/:id(.:format)    posts#destroy root_path   /   posts#index about_path  /about(.:format)    pages#about 

i restarted server nothing helps. haven't found hint in similar topics.

thanks

ok, found solution. in gemfile should be:

gem 'devise': git => 'https://github.com/plataformatec/devise.git'

(v. 4.0.0) instead

gem 'devise' '~> 3.3.0'

devise 3.3.0 not compatible rails 4.2.

thanks