Q:

paperclip Ruby on Rails 4 install Error?

after adding gem and bundle install, I tried to generate paperclip but I get error? 
In GemFile         
      gem "paperclip", "~> 4.1"

In command line:
 $   rails generate paperclip user avatar

Error I get:
   /Users/amirna/.rvm/gems/ruby-2.1.1/gems/railties-4.1.0/lib/rails/generators/actions/create_migration.rb:13:in `migration_file_name': protected method `migration_file_name' called for #<PaperclipGenerator:0x007fc6c7e43690> (NoMethodError)
from /Users/amirna/.rvm/gems/ruby-2.1.1/gems/railties-4.1.0/lib/rails/generators/actions/create_migration.rb:34:in `existing_migration'
from /Users/amirna/.rvm/gems/ruby-2.1.1/gems/thor-0.19.1/lib/thor/actions/empty_directory.rb:112:in `invoke_with_conflict_check'
from /Users/amirna/.rvm/gems/ruby-2.1.1/gems/thor-0.19.1/lib/thor/actions/create_file.rb:60:in `invoke!'

A:

It is a documented issue at PaperClip - https://github.com/thoughtbot/paperclip/issues/1495 
Change that to : 
gem 'paperclip', github: 'thoughtbot/paperclip'

