Active admin install error

I have an error, when try to run command:

rails g active_admin:install

The error is /home/user1/.rvm/gems/ruby-2.1.4@rails418/bundler/gems/active_admin-6bde1f57ec5f/lib/generators/active_admin/devise/devise_generator.rb:21:inrescue in install_devise': uninitialized constant ActiveAdmin::Generators::DeviseGenerator::DependencyError (NameError) ` Active admin and devise gems are install. The only problem is when I generate active admin. I use Rails-4.1.8 and ruby-2.1.4.

Thanks for help and good day.